Integrate commit-graph into 'fsck' and 'gc' #6
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Signed-off-by: Derrick Stolee <[email protected]>
The GRAPH_MIN_SIZE macro should be the smallest size of a parsable commit-graph file. However, the minimum number of chunks was wrong. It is possible to write a commit-graph file with zero commits, and that violates this macro's value. Rewrite the macro, and use extra macros to better explain the magic constants. Signed-off-by: Derrick Stolee <[email protected]>
Before verifying a commit-graph file against the object database, we need to parse all commits from the given commit-graph file. Create parse_commit_in_graph_one() to target a given struct commit_graph. Signed-off-by: Derrick Stolee <[email protected]>
In anticipation of verifying commit-graph file contents against the object database, create parse_commit_internal() to allow side-stepping the commit-graph file and parse directly from the object database. Due to the use of generation numbers, this method should not be called unless the intention is explicit in avoiding commits from the commit-graph file. Signed-off-by: Derrick Stolee <[email protected]>
When lazy-loading a tree for a commit, it will be important to select the tree from a specific struct commit_graph. Create a new method that specifies the commit-graph file and use that in get_commit_tree_in_graph(). Signed-off-by: Derrick Stolee <[email protected]>
If the commit-graph file becomes corrupt, we need a way to verify that its contents match the object database. In the manner of 'git fsck' we will implement a 'git commit-graph verify' subcommand to report all issues with the file. Add the 'verify' subcommand to the 'commit-graph' builtin and its documentation. The subcommand is currently a no-op except for loading the commit-graph into memory, which may trigger run-time errors that would be caught by normal use. Add a simple test that ensures the command returns a zero error code. If no commit-graph file exists, this is an acceptable state. Do not report any errors. Helped-by: Ramsay Jones <[email protected]> Signed-off-by: Derrick Stolee <[email protected]>
This is the first of several commits that add a test to check that 'git commit-graph verify' catches corruption in the commit-graph file. The first test checks that the command catches an error in the file signature. This is a check that exists in the existing commit-graph reading code. Add a helper method 'corrupt_graph_and_verify' to the test script t5318-commit-graph.sh. This helper corrupts the commit-graph file at a certain location, runs 'git commit-graph verify', and reports the output to the 'err' file. This data is filtered to remove the lines added by 'test_must_fail' when the test is run verbosely. Then, the output is checked to contain a specific error message. Most messages from 'git commit-graph verify' will not be marked for translation. There will be one exception: the message that reports an invalid checksum will be marked for translation, as that is the only message that is intended for a typical user. Helped-by: Szeder Gábor <[email protected]> Signed-off-by: Derrick Stolee <[email protected]>
The commit-graph file requires the following three chunks: * OID Fanout * OID Lookup * Commit Data If any of these are missing, then the 'verify' subcommand should report a failure. This includes the chunk IDs malformed or the chunk count is truncated. Signed-off-by: Derrick Stolee <[email protected]>
In the commit-graph file, the OID fanout chunk provides an index into the OID lookup. The 'verify' subcommand should find incorrect values in the fanout. Similarly, the 'verify' subcommand should find out-of-order values in the OID lookup. Signed-off-by: Derrick Stolee <[email protected]>
In the 'verify' subcommand, load commits directly from the object database to ensure they exist. Parse by skipping the commit-graph. Signed-off-by: Derrick Stolee <[email protected]>
The 'verify' subcommand must compare the commit content parsed from the commit-graph against the content in the object database. Use lookup_commit() and parse_commit_in_graph_one() to parse the commits from the graph and compare against a commit that is loaded separately and parsed directly from the object database. Add checks for the root tree OID. Signed-off-by: Derrick Stolee <[email protected]>
The commit-graph file stores parents in a two-column portion of the commit data chunk. If there is only one parent, then the second column stores 0xFFFFFFFF to indicate no second parent. The 'verify' subcommand checks the parent list for the commit loaded from the commit-graph and the one parsed from the object database. Test these checks for corrupt parents, too many parents, and wrong parents. Add a boundary check to insert_parent_or_die() for when the parent position value is out of range. The octopus merge will be tested in a later commit. Signed-off-by: Derrick Stolee <[email protected]>
While iterating through the commit parents, perform the generation number calculation and compare against the value stored in the commit-graph. The tests demonstrate that having a different set of parents affects the generation number calculation, and this value propagates to descendants. Hence, we drop the single-line condition on the output. Since Git will ship with the commit-graph feature without generation numbers, we need to accept commit-graphs with all generation numbers equal to zero. In this case, ignore the generation number calculation. However, verify that we should never have a mix of zero and non-zero generation numbers. Create a test that sets one commit to generation zero and all following commits report a failure as they have non-zero generation in a file that contains generation number zero. Signed-off-by: Derrick Stolee <[email protected]>
Signed-off-by: Derrick Stolee <[email protected]>
The commit-graph file has an extra chunk to store the parent int-ids for parents beyond the first parent for octopus merges. Our test repo has a single octopus merge that we can manipulate to demonstrate the 'verify' subcommand detects incorrect values in that chunk. Signed-off-by: Derrick Stolee <[email protected]>
The commit-graph file ends with a SHA1 hash of the previous contents. If a commit-graph file has errors but the checksum hash is correct, then we know that the problem is a bug in Git and not simply file corruption after-the-fact. Compute the checksum right away so it is the first error that appears, and make the message translatable since this error can be "corrected" by a user by simply deleting the file and recomputing. The rest of the errors are useful only to developers. Be sure to continue checking the rest of the file data if the checksum is wrong. This is important for our tests, as we break the checksum as we modify bytes of the commit-graph file. Signed-off-by: Derrick Stolee <[email protected]>
If core.commitGraph is true, verify the contents of the commit-graph during 'git fsck' using the 'git commit-graph verify' subcommand. Run this check on all alternates, as well. We use a new process for two reasons: 1. The subcommand decouples the details of loading and verifying a commit-graph file from the other fsck details. 2. The commit-graph verification requires the commits to be loaded in a specific order to guarantee we parse from the commit-graph file for some objects and from the object database for others. Signed-off-by: Derrick Stolee <[email protected]>
Signed-off-by: Derrick Stolee <[email protected]>
When writing commit-graph files, it can be convenient to ask for all reachable commits (starting at the ref set) in the resulting file. This is particularly helpful when writing to stdin is complicated, such as a future integration with 'git gc'. Signed-off-by: Derrick Stolee <[email protected]>
The commit-graph file is a very helpful feature for speeding up git operations. In order to make it more useful, make it possible to write the commit-graph file during standard garbage collection operations. Add a 'gc.commitGraph' config setting that triggers writing a commit-graph file after any non-trivial 'git gc' command. Defaults to false while the commit-graph feature matures. We specifically do not want to have this on by default until the commit-graph feature is fully integrated with history-modifying features like shallow clones. Helped-by: Ævar Arnfjörð Bjarmason <[email protected]> Signed-off-by: Derrick Stolee <[email protected]>
The commit-graph feature is now integrated with 'fsck' and 'gc', so remove those items from the "Future Work" section of the commit-graph design document. Also remove the section on lazy-loading trees, as that was completed in an earlier patch series. Signed-off-by: Derrick Stolee <[email protected]>
Member
|
/allow derrickstolee |
|
An error occurred while processing: Error: User derrickstolee lacks permission for this. |
Member
|
/allow derrickstolee |
|
User derrickstolee is now allowed to use GitGitGadget. |
dscho
pushed a commit
that referenced
this pull request
Feb 23, 2021
write_commit_graph initialises topo_levels using init_topo_level_slab(), next it calls compute_topological_levels() which can cause the slab to grow, we therefore need to clear the slab again using clear_topo_level_slab() when we're done. First introduced in 72a2bfc (commit-graph: add a slab to store topological levels, 2021-01-16). LeakSanitizer output: ==1026==ERROR: LeakSanitizer: detected memory leaks Direct leak of 8 byte(s) in 1 object(s) allocated from: #0 0x498ae9 in realloc /src/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:164:3 #1 0xafbed8 in xrealloc /src/git/wrapper.c:126:8 #2 0x7966d1 in topo_level_slab_at_peek /src/git/commit-graph.c:71:1 #3 0x7965e0 in topo_level_slab_at /src/git/commit-graph.c:71:1 #4 0x78fbf5 in compute_topological_levels /src/git/commit-graph.c:1472:12 #5 0x78c5c3 in write_commit_graph /src/git/commit-graph.c:2456:2 #6 0x535c5f in graph_write /src/git/builtin/commit-graph.c:299:6 #7 0x5350ca in cmd_commit_graph /src/git/builtin/commit-graph.c:337:11 #8 0x4cddb1 in run_builtin /src/git/git.c:453:11 #9 0x4cabe2 in handle_builtin /src/git/git.c:704:3 #10 0x4cd084 in run_argv /src/git/git.c:771:4 #11 0x4ca424 in cmd_main /src/git/git.c:902:19 #12 0x707fb6 in main /src/git/common-main.c:52:11 #13 0x7fee4249383f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f) Indirect leak of 524256 byte(s) in 1 object(s) allocated from: #0 0x498942 in calloc /src/llvm-project/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3 #1 0xafc088 in xcalloc /src/git/wrapper.c:140:8 #2 0x796870 in topo_level_slab_at_peek /src/git/commit-graph.c:71:1 #3 0x7965e0 in topo_level_slab_at /src/git/commit-graph.c:71:1 #4 0x78fbf5 in compute_topological_levels /src/git/commit-graph.c:1472:12 #5 0x78c5c3 in write_commit_graph /src/git/commit-graph.c:2456:2 #6 0x535c5f in graph_write /src/git/builtin/commit-graph.c:299:6 #7 0x5350ca in cmd_commit_graph /src/git/builtin/commit-graph.c:337:11 #8 0x4cddb1 in run_builtin /src/git/git.c:453:11 #9 0x4cabe2 in handle_builtin /src/git/git.c:704:3 #10 0x4cd084 in run_argv /src/git/git.c:771:4 #11 0x4ca424 in cmd_main /src/git/git.c:902:19 #12 0x707fb6 in main /src/git/common-main.c:52:11 #13 0x7fee4249383f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2083f) SUMMARY: AddressSanitizer: 524264 byte(s) leaked in 2 allocation(s). Signed-off-by: Andrzej Hunt <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
dscho
pushed a commit
that referenced
this pull request
Mar 8, 2021
This leak has existed since: 9ab55da (git symbolic-ref --delete $symref, 2012-10-21) This leak was found when running t0001 with LSAN, see also LSAN output below: Direct leak of 19 byte(s) in 1 object(s) allocated from: #0 0x486514 in strdup /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_interceptors.cpp:452:3 #1 0x9ab048 in xstrdup /home/ahunt/oss-fuzz/git/wrapper.c:29:14 #2 0x8b452f in refs_shorten_unambiguous_ref /home/ahunt/oss-fuzz/git/refs.c #3 0x8b47e8 in shorten_unambiguous_ref /home/ahunt/oss-fuzz/git/refs.c:1287:9 #4 0x679fce in check_symref /home/ahunt/oss-fuzz/git/builtin/symbolic-ref.c:28:14 #5 0x679ad8 in cmd_symbolic_ref /home/ahunt/oss-fuzz/git/builtin/symbolic-ref.c:70:9 #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #10 0x69cc6e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #11 0x7f98388a4349 in __libc_start_main (/lib64/libc.so.6+0x24349) Signed-off-by: Andrzej Hunt <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
dscho
pushed a commit
that referenced
this pull request
Mar 8, 2021
dwim_ref() allocs a new string into ref. Instead of setting to NULL to discard it, we can FREE_AND_NULL. This leak appears to have been introduced in: 4cf76f6 (builtin/reset: compute checkout metadata for reset, 2020-03-16) This leak was found when running t0001 with LSAN, see also LSAN output below: Direct leak of 5 byte(s) in 1 object(s) allocated from: #0 0x486514 in strdup /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_interceptors.cpp:452:3 #1 0x9a7108 in xstrdup /home/ahunt/oss-fuzz/git/wrapper.c:29:14 #2 0x8add6b in expand_ref /home/ahunt/oss-fuzz/git/refs.c:670:12 #3 0x8ad777 in repo_dwim_ref /home/ahunt/oss-fuzz/git/refs.c:644:22 #4 0x6394af in dwim_ref /home/ahunt/oss-fuzz/git/./refs.h:162:9 #5 0x637e5c in cmd_reset /home/ahunt/oss-fuzz/git/builtin/reset.c:426:4 #6 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11 #7 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3 #8 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4 #9 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19 #10 0x69c5ce in main /home/ahunt/oss-fuzz/git/common-main.c:52:11 #11 0x7f57ebb9d349 in __libc_start_main (/lib64/libc.so.6+0x24349) Signed-off-by: Andrzej Hunt <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Dec 30, 2024
There's a race with LSan when spawning threads and one of the threads
calls die(). We worked around one such problem with index-pack in the
previous commit, but it exists in git-grep, too. You can see it with:
make SANITIZE=leak THREAD_BARRIER_PTHREAD=YesOnLinux
cd t
./t0003-attributes.sh --stress
which fails pretty quickly with:
==git==4096424==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 32 byte(s) in 1 object(s) allocated from:
#0 0x7f906de14556 in realloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:98
#1 0x7f906dc9d2c1 in __pthread_getattr_np nptl/pthread_getattr_np.c:180
#2 0x7f906de2500d in __sanitizer::GetThreadStackTopAndBottom(bool, unsigned long*, unsigned long*) ../../../../src/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cpp:150
#3 0x7f906de25187 in __sanitizer::GetThreadStackAndTls(bool, unsigned long*, unsigned long*, unsigned long*, unsigned long*) ../../../../src/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cpp:614
#4 0x7f906de17d18 in __lsan::ThreadStart(unsigned int, unsigned long long, __sanitizer::ThreadType) ../../../../src/libsanitizer/lsan/lsan_posix.cpp:53
#5 0x7f906de143a9 in ThreadStartFunc<false> ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:431
#6 0x7f906dc9bf51 in start_thread nptl/pthread_create.c:447
#7 0x7f906dd1a677 in __clone3 ../sysdeps/unix/sysv/linux/x86_64/clone3.S:78
As with the previous commit, we can fix this by inserting a barrier that
makes sure all threads have finished their setup before continuing. But
there's one twist in this case: the thread which calls die() is not one
of the worker threads, but the main thread itself!
So we need the main thread to wait in the barrier, too, until all
threads have gotten to it. And thus we initialize the barrier for
num_threads+1, to account for all of the worker threads plus the main
one.
If we then test as above, t0003 should run indefinitely.
Signed-off-by: Jeff King <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Dec 30, 2024
In 1b9e9be (csum-file.c: use unsafe SHA-1 implementation when available, 2024-09-26) we have converted our `struct hashfile` to use the unsafe SHA1 backend, which results in a significant speedup. One needs to be careful with how to use that structure now though because callers need to consistently use either the safe or unsafe variants of SHA1, as otherwise one can easily trigger corruption. As it turns out, we have one inconsistent usage in our tree because we directly initialize `struct hashfile_checkpoint::ctx` with the safe variant of SHA1, but end up writing to that context with the unsafe ones. This went unnoticed so far because our CI systems do not exercise different hash functions for these two backends, and consequently safe and unsafe variants are equivalent. But when using SHA1DC as safe and OpenSSL as unsafe backend this leads to a crash an t1050: ++ git -c core.compression=0 add large1 AddressSanitizer:DEADLYSIGNAL ================================================================= ==1367==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000040 (pc 0x7ffff7a01a99 bp 0x507000000db0 sp 0x7fffffff5690 T0) ==1367==The signal is caused by a READ memory access. ==1367==Hint: address points to the zero page. #0 0x7ffff7a01a99 in EVP_MD_CTX_copy_ex (/nix/store/h1ydpxkw9qhjdxjpic1pdc2nirggyy6f-openssl-3.3.2/lib/libcrypto.so.3+0x201a99) (BuildId: 41746a580d39075fc85e8c8065b6c07fb34e97d4) #1 0x555555ddde56 in openssl_SHA1_Clone ../sha1/openssl.h:40:2 #2 0x555555dce2fc in git_hash_sha1_clone_unsafe ../object-file.c:123:2 #3 0x555555c2d5f8 in hashfile_checkpoint ../csum-file.c:211:2 #4 0x555555b9905d in deflate_blob_to_pack ../bulk-checkin.c:286:4 #5 0x555555b98ae9 in index_blob_bulk_checkin ../bulk-checkin.c:362:15 #6 0x555555ddab62 in index_blob_stream ../object-file.c:2756:9 #7 0x555555dda420 in index_fd ../object-file.c:2778:9 #8 0x555555ddad76 in index_path ../object-file.c:2796:7 #9 0x555555e947f3 in add_to_index ../read-cache.c:771:7 #10 0x555555e954a4 in add_file_to_index ../read-cache.c:804:9 #11 0x5555558b5c39 in add_files ../builtin/add.c:355:7 #12 0x5555558b412e in cmd_add ../builtin/add.c:578:18 #13 0x555555b1f493 in run_builtin ../git.c:480:11 #14 0x555555b1bfef in handle_builtin ../git.c:740:9 #15 0x555555b1e6f4 in run_argv ../git.c:807:4 #16 0x555555b1b87a in cmd_main ../git.c:947:19 #17 0x5555561649e6 in main ../common-main.c:64:11 #18 0x7ffff742a1fb in __libc_start_call_main (/nix/store/65h17wjrrlsj2rj540igylrx7fqcd6vq-glibc-2.40-36/lib/libc.so.6+0x2a1fb) (BuildId: bf320110569c8ec2425e9a0c5e4eb7e97f1fb6e4) #19 0x7ffff742a2b8 in __libc_start_main@GLIBC_2.2.5 (/nix/store/65h17wjrrlsj2rj540igylrx7fqcd6vq-glibc-2.40-36/lib/libc.so.6+0x2a2b8) (BuildId: bf320110569c8ec2425e9a0c5e4eb7e97f1fb6e4) #20 0x555555772c84 in _start (git+0x21ec84) ==1367==Register values: rax = 0x0000511000001080 rbx = 0x0000000000000000 rcx = 0x000000000000000c rdx = 0x0000000000000000 rdi = 0x0000000000000000 rsi = 0x0000507000000db0 rbp = 0x0000507000000db0 rsp = 0x00007fffffff5690 r8 = 0x0000000000000000 r9 = 0x0000000000000000 r10 = 0x0000000000000000 r11 = 0x00007ffff7a01a30 r12 = 0x0000000000000000 r13 = 0x00007fffffff6b38 r14 = 0x00007ffff7ffd000 r15 = 0x00005555563b9910 AddressSanitizer can not provide additional info. SUMMARY: AddressSanitizer: SEGV (/nix/store/h1ydpxkw9qhjdxjpic1pdc2nirggyy6f-openssl-3.3.2/lib/libcrypto.so.3+0x201a99) (BuildId: 41746a580d39075fc85e8c8065b6c07fb34e97d4) in EVP_MD_CTX_copy_ex ==1367==ABORTING ./test-lib.sh: line 1023: 1367 Aborted git $config add large1 error: last command exited with $?=134 not ok 4 - add with -c core.compression=0 Fix the issue by using the unsafe variant instead. Signed-off-by: Patrick Steinhardt <[email protected]> Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Dec 30, 2024
Same as with the preceding commit, git-fast-import(1) is using the safe
variant to initialize a hashfile checkpoint. This leads to a segfault
when passing the checkpoint into the hashfile subsystem because it would
use the unsafe variants instead:
++ git --git-dir=R/.git fast-import --big-file-threshold=1
AddressSanitizer:DEADLYSIGNAL
=================================================================
==577126==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000040 (pc 0x7ffff7a01a99 bp 0x5070000009c0 sp 0x7fffffff5b30 T0)
==577126==The signal is caused by a READ memory access.
==577126==Hint: address points to the zero page.
#0 0x7ffff7a01a99 in EVP_MD_CTX_copy_ex (/nix/store/h1ydpxkw9qhjdxjpic1pdc2nirggyy6f-openssl-3.3.2/lib/libcrypto.so.3+0x201a99) (BuildId: 41746a580d39075fc85e8c8065b6c07fb34e97d4)
#1 0x555555ddde56 in openssl_SHA1_Clone ../sha1/openssl.h:40:2
#2 0x555555dce2fc in git_hash_sha1_clone_unsafe ../object-file.c:123:2
#3 0x555555c2d5f8 in hashfile_checkpoint ../csum-file.c:211:2
#4 0x5555559647d1 in stream_blob ../builtin/fast-import.c:1110:2
#5 0x55555596247b in parse_and_store_blob ../builtin/fast-import.c:2031:3
#6 0x555555967f91 in file_change_m ../builtin/fast-import.c:2408:5
#7 0x55555595d8a2 in parse_new_commit ../builtin/fast-import.c:2768:4
#8 0x55555595bb7a in cmd_fast_import ../builtin/fast-import.c:3614:4
#9 0x555555b1f493 in run_builtin ../git.c:480:11
#10 0x555555b1bfef in handle_builtin ../git.c:740:9
#11 0x555555b1e6f4 in run_argv ../git.c:807:4
#12 0x555555b1b87a in cmd_main ../git.c:947:19
#13 0x5555561649e6 in main ../common-main.c:64:11
#14 0x7ffff742a1fb in __libc_start_call_main (/nix/store/65h17wjrrlsj2rj540igylrx7fqcd6vq-glibc-2.40-36/lib/libc.so.6+0x2a1fb) (BuildId: bf320110569c8ec2425e9a0c5e4eb7e97f1fb6e4)
#15 0x7ffff742a2b8 in __libc_start_main@GLIBC_2.2.5 (/nix/store/65h17wjrrlsj2rj540igylrx7fqcd6vq-glibc-2.40-36/lib/libc.so.6+0x2a2b8) (BuildId: bf320110569c8ec2425e9a0c5e4eb7e97f1fb6e4)
#16 0x555555772c84 in _start (git+0x21ec84)
==577126==Register values:
rax = 0x0000511000000cc0 rbx = 0x0000000000000000 rcx = 0x000000000000000c rdx = 0x0000000000000000
rdi = 0x0000000000000000 rsi = 0x00005070000009c0 rbp = 0x00005070000009c0 rsp = 0x00007fffffff5b30
r8 = 0x0000000000000000 r9 = 0x0000000000000000 r10 = 0x0000000000000000 r11 = 0x00007ffff7a01a30
r12 = 0x0000000000000000 r13 = 0x00007fffffff6b60 r14 = 0x00007ffff7ffd000 r15 = 0x00005555563b9910
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV (/nix/store/h1ydpxkw9qhjdxjpic1pdc2nirggyy6f-openssl-3.3.2/lib/libcrypto.so.3+0x201a99) (BuildId: 41746a580d39075fc85e8c8065b6c07fb34e97d4) in EVP_MD_CTX_copy_ex
==577126==ABORTING
./test-lib.sh: line 1039: 577126 Aborted git --git-dir=R/.git fast-import --big-file-threshold=1 < input
error: last command exited with $?=134
not ok 167 - R: blob bigger than threshold
The segfault is only exposed in case the unsafe and safe backends are
different from one another.
Fix the issue by initializing the context with the unsafe SHA1 variant.
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Jan 1, 2025
Our CI jobs sometimes see false positive leaks like this:
=================================================================
==3904583==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 32 byte(s) in 1 object(s) allocated from:
#0 0x7fa790d01986 in __interceptor_realloc ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:98
#1 0x7fa790add769 in __pthread_getattr_np nptl/pthread_getattr_np.c:180
#2 0x7fa790d117c5 in __sanitizer::GetThreadStackTopAndBottom(bool, unsigned long*, unsigned long*) ../../../../src/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cpp:150
#3 0x7fa790d11957 in __sanitizer::GetThreadStackAndTls(bool, unsigned long*, unsigned long*, unsigned long*, unsigned long*) ../../../../src/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cpp:598
#4 0x7fa790d03fe8 in __lsan::ThreadStart(unsigned int, unsigned long long, __sanitizer::ThreadType) ../../../../src/libsanitizer/lsan/lsan_posix.cpp:51
#5 0x7fa790d013fd in __lsan_thread_start_func ../../../../src/libsanitizer/lsan/lsan_interceptors.cpp:440
#6 0x7fa790adc3eb in start_thread nptl/pthread_create.c:444
#7 0x7fa790b5ca5b in clone3 ../sysdeps/unix/sysv/linux/x86_64/clone3.S:81
This is not a leak in our code, but appears to be a race between one
thread calling exit() while another one is in LSan's stack setup code.
You can reproduce it easily by running t0003 or t5309 with --stress
(these trigger it because of the threading in git-grep and index-pack
respectively).
This may be a bug in LSan, but regardless of whether it is eventually
fixed, it is useful to work around it so that we stop seeing these false
positives.
We can recognize it by the mention of the sanitizer functions in the
DEDUP_TOKEN line. With this patch, the scripts mentioned above should
run with --stress indefinitely.
Signed-off-by: Jeff King <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Jan 29, 2025
When trying to create a Unix socket in a path that exceeds the maximum
socket name length we try to first change the directory into the parent
folder before creating the socket to reduce the length of the name. When
this fails we error out of `unix_sockaddr_init()` with an error code,
which indicates to the caller that the context has not been initialized.
Consequently, they don't release that context.
This leads to a memory leak: when we have already populated the context
with the original directory that we need to chdir(3p) back into, but
then the chdir(3p) into the socket's parent directory fails, then we
won't release the original directory's path. The leak is exposed by
t0301, but only via Meson with `meson setup -Dsanitize=leak`:
Direct leak of 129 byte(s) in 1 object(s) allocated from:
#0 0x5555555e85c6 in realloc.part.0 lsan_interceptors.cpp.o
#1 0x55555590e3d6 in xrealloc ../wrapper.c:140:8
#2 0x5555558c8fc6 in strbuf_grow ../strbuf.c:114:2
#3 0x5555558cacab in strbuf_getcwd ../strbuf.c:605:3
#4 0x555555923ff6 in unix_sockaddr_init ../unix-socket.c:65:7
#5 0x555555923e42 in unix_stream_connect ../unix-socket.c:84:6
#6 0x55555562a984 in send_request ../builtin/credential-cache.c:46:11
#7 0x55555562a89e in do_cache ../builtin/credential-cache.c:108:6
#8 0x55555562a655 in cmd_credential_cache ../builtin/credential-cache.c:178:3
#9 0x555555700547 in run_builtin ../git.c:480:11
#10 0x5555556ff0e0 in handle_builtin ../git.c:740:9
#11 0x5555556ffee8 in run_argv ../git.c:807:4
#12 0x5555556fee6b in cmd_main ../git.c:947:19
#13 0x55555593f689 in main ../common-main.c:64:11
#14 0x7ffff7a2a1fb in __libc_start_call_main (/nix/store/h7zcxabfxa7v5xdna45y2hplj31ncf8a-glibc-2.40-36/lib/libc.so.6+0x2a1fb) (BuildId: 0a855678aa0cb573cecbb2bcc73ab8239ec472d0)
#15 0x7ffff7a2a2b8 in __libc_start_main@GLIBC_2.2.5 (/nix/store/h7zcxabfxa7v5xdna45y2hplj31ncf8a-glibc-2.40-36/lib/libc.so.6+0x2a2b8) (BuildId: 0a855678aa0cb573cecbb2bcc73ab8239ec472d0)
#16 0x5555555ad1d4 in _start (git+0x591d4)
DEDUP_TOKEN: ___interceptor_realloc.part.0--xrealloc--strbuf_grow--strbuf_getcwd--unix_sockaddr_init--unix_stream_connect--send_request--do_cache--cmd_credential_cache--run_builtin--handle_builtin--run_argv--cmd_main--main--__libc_start_call_main--__libc_start_main@GLIBC_2.2.5--_start
SUMMARY: LeakSanitizer: 129 byte(s) leaked in 1 allocation(s).
Fix this leak.
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Jan 29, 2025
We don't free the result of `remote_default_branch()`, leading to a
memory leak. This leak is exposed by t9211, but only when run with Meson
via `meson setup -Dsanitize=leak`:
Direct leak of 5 byte(s) in 1 object(s) allocated from:
#0 0x5555555cfb93 in malloc (scalar+0x7bb93)
#1 0x5555556b05c2 in do_xmalloc ../wrapper.c:55:8
#2 0x5555556b06c4 in do_xmallocz ../wrapper.c:89:8
#3 0x5555556b0656 in xmallocz ../wrapper.c:97:9
#4 0x5555556b0728 in xmemdupz ../wrapper.c:113:16
#5 0x5555556b07a7 in xstrndup ../wrapper.c:119:9
#6 0x5555555d3a4b in remote_default_branch ../scalar.c:338:14
#7 0x5555555d20e6 in cmd_clone ../scalar.c:493:28
#8 0x5555555d196b in cmd_main ../scalar.c:992:14
#9 0x5555557c4059 in main ../common-main.c:64:11
#10 0x7ffff7a2a1fb in __libc_start_call_main (/nix/store/h7zcxabfxa7v5xdna45y2hplj31ncf8a-glibc-2.40-36/lib/libc.so.6+0x2a1fb) (BuildId: 0a855678aa0cb573cecbb2bcc73ab8239ec472d0)
#11 0x7ffff7a2a2b8 in __libc_start_main@GLIBC_2.2.5 (/nix/store/h7zcxabfxa7v5xdna45y2hplj31ncf8a-glibc-2.40-36/lib/libc.so.6+0x2a2b8) (BuildId: 0a855678aa0cb573cecbb2bcc73ab8239ec472d0)
#12 0x555555592054 in _start (scalar+0x3e054)
DEDUP_TOKEN: __interceptor_malloc--do_xmalloc--do_xmallocz--xmallocz--xmemdupz--xstrndup--remote_default_branch--cmd_clone--cmd_main--main--__libc_start_call_main--__libc_start_main@GLIBC_2.2.5--_start
SUMMARY: LeakSanitizer: 5 byte(s) leaked in 1 allocation(s).
As the `branch` variable may contain a string constant obtained from
parsing command line arguments we cannot free the leaking variable
directly. Instead, introduce a new `branch_to_free` variable that only
ever gets assigned the allocated string and free that one to plug the
leak.
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Jan 30, 2025
When trying to create a Unix socket in a path that exceeds the maximum
socket name length we try to first change the directory into the parent
folder before creating the socket to reduce the length of the name. When
this fails we error out of `unix_sockaddr_init()` with an error code,
which indicates to the caller that the context has not been initialized.
Consequently, they don't release that context.
This leads to a memory leak: when we have already populated the context
with the original directory that we need to chdir(3p) back into, but
then the chdir(3p) into the socket's parent directory fails, then we
won't release the original directory's path. The leak is exposed by
t0301, but only when running tests in a directory hierarchy whose path
is long enough to make the socket name length exceed the maximum socket
name length:
Direct leak of 129 byte(s) in 1 object(s) allocated from:
#0 0x5555555e85c6 in realloc.part.0 lsan_interceptors.cpp.o
#1 0x55555590e3d6 in xrealloc ../wrapper.c:140:8
#2 0x5555558c8fc6 in strbuf_grow ../strbuf.c:114:2
#3 0x5555558cacab in strbuf_getcwd ../strbuf.c:605:3
#4 0x555555923ff6 in unix_sockaddr_init ../unix-socket.c:65:7
#5 0x555555923e42 in unix_stream_connect ../unix-socket.c:84:6
#6 0x55555562a984 in send_request ../builtin/credential-cache.c:46:11
#7 0x55555562a89e in do_cache ../builtin/credential-cache.c:108:6
#8 0x55555562a655 in cmd_credential_cache ../builtin/credential-cache.c:178:3
#9 0x555555700547 in run_builtin ../git.c:480:11
#10 0x5555556ff0e0 in handle_builtin ../git.c:740:9
#11 0x5555556ffee8 in run_argv ../git.c:807:4
#12 0x5555556fee6b in cmd_main ../git.c:947:19
#13 0x55555593f689 in main ../common-main.c:64:11
#14 0x7ffff7a2a1fb in __libc_start_call_main (/nix/store/h7zcxabfxa7v5xdna45y2hplj31ncf8a-glibc-2.40-36/lib/libc.so.6+0x2a1fb) (BuildId: 0a855678aa0cb573cecbb2bcc73ab8239ec472d0)
#15 0x7ffff7a2a2b8 in __libc_start_main@GLIBC_2.2.5 (/nix/store/h7zcxabfxa7v5xdna45y2hplj31ncf8a-glibc-2.40-36/lib/libc.so.6+0x2a2b8) (BuildId: 0a855678aa0cb573cecbb2bcc73ab8239ec472d0)
#16 0x5555555ad1d4 in _start (git+0x591d4)
DEDUP_TOKEN: ___interceptor_realloc.part.0--xrealloc--strbuf_grow--strbuf_getcwd--unix_sockaddr_init--unix_stream_connect--send_request--do_cache--cmd_credential_cache--run_builtin--handle_builtin--run_argv--cmd_main--main--__libc_start_call_main--__libc_start_main@GLIBC_2.2.5--_start
SUMMARY: LeakSanitizer: 129 byte(s) leaked in 1 allocation(s).
Fix this leak.
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Jan 30, 2025
We don't free the result of `remote_default_branch()`, leading to a
memory leak. This leak is exposed by t9211, but only when run with Meson
with the `-Db_sanitize=leak` option:
Direct leak of 5 byte(s) in 1 object(s) allocated from:
#0 0x5555555cfb93 in malloc (scalar+0x7bb93)
#1 0x5555556b05c2 in do_xmalloc ../wrapper.c:55:8
#2 0x5555556b06c4 in do_xmallocz ../wrapper.c:89:8
#3 0x5555556b0656 in xmallocz ../wrapper.c:97:9
#4 0x5555556b0728 in xmemdupz ../wrapper.c:113:16
#5 0x5555556b07a7 in xstrndup ../wrapper.c:119:9
#6 0x5555555d3a4b in remote_default_branch ../scalar.c:338:14
#7 0x5555555d20e6 in cmd_clone ../scalar.c:493:28
#8 0x5555555d196b in cmd_main ../scalar.c:992:14
#9 0x5555557c4059 in main ../common-main.c:64:11
#10 0x7ffff7a2a1fb in __libc_start_call_main (/nix/store/h7zcxabfxa7v5xdna45y2hplj31ncf8a-glibc-2.40-36/lib/libc.so.6+0x2a1fb) (BuildId: 0a855678aa0cb573cecbb2bcc73ab8239ec472d0)
#11 0x7ffff7a2a2b8 in __libc_start_main@GLIBC_2.2.5 (/nix/store/h7zcxabfxa7v5xdna45y2hplj31ncf8a-glibc-2.40-36/lib/libc.so.6+0x2a2b8) (BuildId: 0a855678aa0cb573cecbb2bcc73ab8239ec472d0)
#12 0x555555592054 in _start (scalar+0x3e054)
DEDUP_TOKEN: __interceptor_malloc--do_xmalloc--do_xmallocz--xmallocz--xmemdupz--xstrndup--remote_default_branch--cmd_clone--cmd_main--main--__libc_start_call_main--__libc_start_main@GLIBC_2.2.5--_start
SUMMARY: LeakSanitizer: 5 byte(s) leaked in 1 allocation(s).
As the `branch` variable may contain a string constant obtained from
parsing command line arguments we cannot free the leaking variable
directly. Instead, introduce a new `branch_to_free` variable that only
ever gets assigned the allocated string and free that one to plug the
leak.
It is unclear why the leak isn't flagged when running the test via our
Makefile.
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Jul 22, 2025
find_cfg_ent() allocates a struct reflog_expire_entry_option via
FLEX_ALLOC_MEM and inserts it into a linked list in the
reflog_expire_options structure. The entries in this list are never
freed, resulting in a leak in cmd_reflog_expire and the gc reflog expire
maintenance task:
Direct leak of 39 byte(s) in 1 object(s) allocated from:
#0 0x7ff975ee6883 in calloc (/lib64/libasan.so.8+0xe6883)
#1 0x0000010edada in xcalloc ../wrapper.c:154
#2 0x000000df0898 in find_cfg_ent ../reflog.c:28
#3 0x000000df0898 in reflog_expire_config ../reflog.c:70
#4 0x00000095c451 in configset_iter ../config.c:2116
#5 0x0000006d29e7 in git_config ../config.h:724
#6 0x0000006d29e7 in cmd_reflog_expire ../builtin/reflog.c:205
#7 0x0000006d504c in cmd_reflog ../builtin/reflog.c:419
#8 0x0000007e4054 in run_builtin ../git.c:480
#9 0x0000007e4054 in handle_builtin ../git.c:746
#10 0x0000007e8a35 in run_argv ../git.c:813
#11 0x0000007e8a35 in cmd_main ../git.c:953
#12 0x000000441e8f in main ../common-main.c:9
#13 0x7ff9754115f4 in __libc_start_call_main (/lib64/libc.so.6+0x35f4)
#14 0x7ff9754116a7 in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x36a7)
#15 0x000000444184 in _start (/home/jekeller/libexec/git-core/git+0x444184)
Close this leak by adding a reflog_clear_expire_config() function which
iterates the linked list and frees its elements. Call it upon exit of
cmd_reflog_expire() and reflog_expire_condition().
Signed-off-by: Jacob Keller <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Jul 23, 2025
find_cfg_ent() allocates a struct reflog_expire_entry_option via
FLEX_ALLOC_MEM and inserts it into a linked list in the
reflog_expire_options structure. The entries in this list are never
freed, resulting in a leak in cmd_reflog_expire and the gc reflog expire
maintenance task:
Direct leak of 39 byte(s) in 1 object(s) allocated from:
#0 0x7ff975ee6883 in calloc (/lib64/libasan.so.8+0xe6883)
#1 0x0000010edada in xcalloc ../wrapper.c:154
#2 0x000000df0898 in find_cfg_ent ../reflog.c:28
#3 0x000000df0898 in reflog_expire_config ../reflog.c:70
#4 0x00000095c451 in configset_iter ../config.c:2116
#5 0x0000006d29e7 in git_config ../config.h:724
#6 0x0000006d29e7 in cmd_reflog_expire ../builtin/reflog.c:205
#7 0x0000006d504c in cmd_reflog ../builtin/reflog.c:419
#8 0x0000007e4054 in run_builtin ../git.c:480
#9 0x0000007e4054 in handle_builtin ../git.c:746
#10 0x0000007e8a35 in run_argv ../git.c:813
#11 0x0000007e8a35 in cmd_main ../git.c:953
#12 0x000000441e8f in main ../common-main.c:9
#13 0x7ff9754115f4 in __libc_start_call_main (/lib64/libc.so.6+0x35f4)
#14 0x7ff9754116a7 in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x36a7)
#15 0x000000444184 in _start (/home/jekeller/libexec/git-core/git+0x444184)
Close this leak by adding a reflog_clear_expire_config() function which
iterates the linked list and frees its elements. Call it upon exit of
cmd_reflog_expire() and reflog_expire_condition().
Add a basic test which covers this leak. While at it, cover the
functionality from commit commit 3cb22b8 (Per-ref reflog expiry
configuration, 2008-06-15). We've had this support for years, but lacked
any tests.
Co-developed-by: Jeff King <[email protected]>
Signed-off-by: Jacob Keller <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Dec 7, 2025
When performing auto-maintenance we check whether commit graphs need to
be generated by counting the number of commits that are reachable by any
reference, but not covered by a commit graph. This search is performed
by iterating through all references and then doing a depth-first search
until we have found enough commits that are not present in the commit
graph.
This logic has a memory leak though:
Direct leak of 16 byte(s) in 1 object(s) allocated from:
#0 0x55555562e433 in malloc (git+0xda433)
#1 0x555555964322 in do_xmalloc ../wrapper.c:55:8
#2 0x5555559642e6 in xmalloc ../wrapper.c:76:9
#3 0x55555579bf29 in commit_list_append ../commit.c:1872:35
#4 0x55555569f160 in dfs_on_ref ../builtin/gc.c:1165:4
#5 0x5555558c33fd in do_for_each_ref_iterator ../refs/iterator.c:431:12
#6 0x5555558af520 in do_for_each_ref ../refs.c:1828:9
#7 0x5555558ac317 in refs_for_each_ref ../refs.c:1833:9
#8 0x55555569e207 in should_write_commit_graph ../builtin/gc.c:1188:11
#9 0x55555569c915 in maintenance_is_needed ../builtin/gc.c:3492:8
#10 0x55555569b76a in cmd_maintenance ../builtin/gc.c:3542:9
#11 0x55555575166a in run_builtin ../git.c:506:11
#12 0x5555557502f0 in handle_builtin ../git.c:779:9
#13 0x555555751127 in run_argv ../git.c:862:4
#14 0x55555575007b in cmd_main ../git.c:984:19
#15 0x5555557523aa in main ../common-main.c:9:11
#16 0x7ffff7a2a4d7 in __libc_start_call_main (/nix/store/xx7cm72qy2c0643cm1ipngd87aqwkcdp-glibc-2.40-66/lib/libc.so.6+0x2a4d7) (BuildId: cddea92d6cba8333be952b5a02fd47d61054c5ab)
#17 0x7ffff7a2a59a in __libc_start_main@GLIBC_2.2.5 (/nix/store/xx7cm72qy2c0643cm1ipngd87aqwkcdp-glibc-2.40-66/lib/libc.so.6+0x2a59a) (BuildId: cddea92d6cba8333be952b5a02fd47d61054c5ab)
#18 0x5555555f0934 in _start (git+0x9c934)
The root cause of this memory leak is our use of `commit_list_append()`.
This function expects as parameters the item to append and the _tail_ of
the list to append. This tail will then be overwritten with the new tail
of the list so that it can be used in subsequent calls. But we call it
with `commit_list_append(parent->item, &stack)`, so we end up losing
everything but the new item.
This issue only surfaces when counting merge commits. Next to being a
memory leak, it also shows that we're in fact miscounting as we only
respect children of the last parent. All previous parents are discarded,
so their children will be disregarded unless they are hit via another
reference.
While crafting a test case for the issue I was puzzled that I couldn't
establish the proper border at which the auto-condition would be
fulfilled. As it turns out, there's another bug: if an object is at the
tip of any reference we don't mark it as seen. Consequently, if it is
reachable via any other reference, we'd count that object twice.
Fix both of these bugs so that we properly count objects without leaking
any memory.
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Dec 7, 2025
In the next commit we are about to move the packfile store into the ODB
source so that we have one store per source. This will lead to a memory
leak in the following commit when reading data from a submodule via
git-grep(1):
Direct leak of 192 byte(s) in 1 object(s) allocated from:
#0 0x55555562e726 in calloc (git+0xda726)
#1 0x555555964734 in xcalloc ../wrapper.c:154:8
#2 0x555555835136 in load_multi_pack_index_one ../midx.c:135:2
#3 0x555555834fd6 in load_multi_pack_index ../midx.c:382:6
#4 0x5555558365b6 in prepare_multi_pack_index_one ../midx.c:716:17
#5 0x55555586c605 in packfile_store_prepare ../packfile.c:1103:3
#6 0x55555586c90c in packfile_store_reprepare ../packfile.c:1118:2
#7 0x5555558546b3 in odb_reprepare ../odb.c:1106:2
#8 0x5555558539e4 in do_oid_object_info_extended ../odb.c:715:4
#9 0x5555558533d1 in odb_read_object_info_extended ../odb.c:862:8
#10 0x5555558540bd in odb_read_object ../odb.c:920:6
#11 0x55555580a330 in grep_source_load_oid ../grep.c:1934:12
#12 0x55555580a13a in grep_source_load ../grep.c:1986:10
#13 0x555555809103 in grep_source_is_binary ../grep.c:2014:7
#14 0x555555807574 in grep_source_1 ../grep.c:1625:8
#15 0x555555807322 in grep_source ../grep.c:1837:10
#16 0x5555556a5c58 in run ../builtin/grep.c:208:10
#17 0x55555562bb42 in void* ThreadStartFunc<false>(void*) lsan_interceptors.cpp.o
#18 0x7ffff7a9a979 in start_thread (/nix/store/xx7cm72qy2c0643cm1ipngd87aqwkcdp-glibc-2.40-66/lib/libc.so.6+0x9a979) (BuildId: cddea92d6cba8333be952b5a02fd47d61054c5ab)
#19 0x7ffff7b22d2b in __GI___clone3 (/nix/store/xx7cm72qy2c0643cm1ipngd87aqwkcdp-glibc-2.40-66/lib/libc.so.6+0x122d2b) (BuildId: cddea92d6cba8333be952b5a02fd47d61054c5ab)
The root caues of this leak is the way we set up and release the
submodule:
1. We use `repo_submodule_init()` to initialize a new repository. This
repository is stored in `repos_to_free`.
2. We now read data from the submodule repository.
3. We then call `repo_clear()` on the submodule repositories.
4. `repo_clear()` calls `odb_free()`.
5. `odb_free()` calls `odb_free_sources()` followed by `odb_close()`.
The issue here is the 5th step: we call `odb_free_sources()` _before_ we
call `odb_close()`. But `odb_free_sources()` already frees all sources,
so the logic that closes them in `odb_close()` now becomes a no-op. As a
consequence, we never explicitly close sources at all.
Fix the leak by closing the store before we free the sources.
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Dec 7, 2025
When pushing to a set of remotes using a nickname for the group, the
client initializes the connection to each remote, talks to the
remote and reads and parses capabilities line, and holds the
capabilities in a file-scope static variable server_capabilities_v1.
There are a few other such file-scope static variables, and these
connections cannot be parallelized until they are refactored to a
structure that keeps track of active connections.
Which is *not* the theme of this patch ;-)
For a single connection, the server_capabilities_v1 variable is
initialized to NULL (at the program initialization), populated when
we talk to the other side, used to look up capabilities of the other
sdie possible multiple times, and the memory is held by the variable
until program exit, without leaking. When talking to multiple remotes,
however, the server capabilities from the second connection overwrites
without freeing the one from the first connection, which leaks.
==1080970==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 421 byte(s) in 2 object(s) allocated from:
#0 0x5615305f849e in strdup (/home/gitster/g/git-jch/bin/bin/git+0x2b349e) (BuildId: 54d149994c9e85374831958f694bd0aa3b8b1e26)
#1 0x561530e76cc4 in xstrdup /home/gitster/w/build/wrapper.c:43:14
#2 0x5615309cd7fa in process_capabilities /home/gitster/w/build/connect.c:243:27
#3 0x5615309cd502 in get_remote_heads /home/gitster/w/build/connect.c:366:4
#4 0x561530e2cb0b in handshake /home/gitster/w/build/transport.c:372:3
#5 0x561530e29ed7 in get_refs_via_connect /home/gitster/w/build/transport.c:398:9
#6 0x561530e26464 in transport_push /home/gitster/w/build/transport.c:1421:16
#7 0x561530800bec in push_with_options /home/gitster/w/build/builtin/push.c:387:8
#8 0x5615307ffb99 in do_push /home/gitster/w/build/builtin/push.c:442:7
#9 0x5615307fe926 in cmd_push /home/gitster/w/build/builtin/push.c:664:7
#10 0x56153065673f in run_builtin /home/gitster/w/build/git.c:506:11
#11 0x56153065342f in handle_builtin /home/gitster/w/build/git.c:779:9
#12 0x561530655b89 in run_argv /home/gitster/w/build/git.c:862:4
#13 0x561530652cba in cmd_main /home/gitster/w/build/git.c:984:19
#14 0x5615308dda0a in main /home/gitster/w/build/common-main.c:9:11
#15 0x7f051651bca7 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
SUMMARY: AddressSanitizer: 421 byte(s) leaked in 2 allocation(s).
Free the capablities data for the previous server before overwriting
it with the next server to plug this leak.
The added test fails without the freeing with SANITIZE=leak; I
somehow couldn't get it fail reliably with SANITIZE=leak,address
though.
Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Dec 9, 2025
When pushing to a set of remotes using a nickname for the group, the
client initializes the connection to each remote, talks to the
remote and reads and parses capabilities line, and holds the
capabilities in a file-scope static variable server_capabilities_v1.
There are a few other such file-scope static variables, and these
connections cannot be parallelized until they are refactored to a
structure that keeps track of active connections.
Which is *not* the theme of this patch ;-)
For a single connection, the server_capabilities_v1 variable is
initialized to NULL (at the program initialization), populated when
we talk to the other side, used to look up capabilities of the other
side possibly multiple times, and the memory is held by the variable
until program exit, without leaking. When talking to multiple remotes,
however, the server capabilities from the second connection overwrites
without freeing the one from the first connection, which leaks.
==1080970==ERROR: LeakSanitizer: detected memory leaks
Direct leak of 421 byte(s) in 2 object(s) allocated from:
#0 0x5615305f849e in strdup (/home/gitster/g/git-jch/bin/bin/git+0x2b349e) (BuildId: 54d149994c9e85374831958f694bd0aa3b8b1e26)
#1 0x561530e76cc4 in xstrdup /home/gitster/w/build/wrapper.c:43:14
#2 0x5615309cd7fa in process_capabilities /home/gitster/w/build/connect.c:243:27
#3 0x5615309cd502 in get_remote_heads /home/gitster/w/build/connect.c:366:4
#4 0x561530e2cb0b in handshake /home/gitster/w/build/transport.c:372:3
#5 0x561530e29ed7 in get_refs_via_connect /home/gitster/w/build/transport.c:398:9
#6 0x561530e26464 in transport_push /home/gitster/w/build/transport.c:1421:16
#7 0x561530800bec in push_with_options /home/gitster/w/build/builtin/push.c:387:8
#8 0x5615307ffb99 in do_push /home/gitster/w/build/builtin/push.c:442:7
#9 0x5615307fe926 in cmd_push /home/gitster/w/build/builtin/push.c:664:7
#10 0x56153065673f in run_builtin /home/gitster/w/build/git.c:506:11
#11 0x56153065342f in handle_builtin /home/gitster/w/build/git.c:779:9
#12 0x561530655b89 in run_argv /home/gitster/w/build/git.c:862:4
#13 0x561530652cba in cmd_main /home/gitster/w/build/git.c:984:19
#14 0x5615308dda0a in main /home/gitster/w/build/common-main.c:9:11
#15 0x7f051651bca7 in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16
SUMMARY: AddressSanitizer: 421 byte(s) leaked in 2 allocation(s).
Free the capablities data for the previous server before overwriting
it with the next server to plug this leak.
The added test fails without the freeing with SANITIZE=leak; I
somehow couldn't get it fail reliably with SANITIZE=leak,address
though.
Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Dec 11, 2025
When performing auto-maintenance we check whether commit graphs need to
be generated by counting the number of commits that are reachable by any
reference, but not covered by a commit graph. This search is performed
by iterating through all references and then doing a depth-first search
until we have found enough commits that are not present in the commit
graph.
This logic has a memory leak though:
Direct leak of 16 byte(s) in 1 object(s) allocated from:
#0 0x55555562e433 in malloc (git+0xda433)
#1 0x555555964322 in do_xmalloc ../wrapper.c:55:8
#2 0x5555559642e6 in xmalloc ../wrapper.c:76:9
#3 0x55555579bf29 in commit_list_append ../commit.c:1872:35
#4 0x55555569f160 in dfs_on_ref ../builtin/gc.c:1165:4
#5 0x5555558c33fd in do_for_each_ref_iterator ../refs/iterator.c:431:12
#6 0x5555558af520 in do_for_each_ref ../refs.c:1828:9
#7 0x5555558ac317 in refs_for_each_ref ../refs.c:1833:9
#8 0x55555569e207 in should_write_commit_graph ../builtin/gc.c:1188:11
#9 0x55555569c915 in maintenance_is_needed ../builtin/gc.c:3492:8
#10 0x55555569b76a in cmd_maintenance ../builtin/gc.c:3542:9
#11 0x55555575166a in run_builtin ../git.c:506:11
#12 0x5555557502f0 in handle_builtin ../git.c:779:9
#13 0x555555751127 in run_argv ../git.c:862:4
#14 0x55555575007b in cmd_main ../git.c:984:19
#15 0x5555557523aa in main ../common-main.c:9:11
#16 0x7ffff7a2a4d7 in __libc_start_call_main (/nix/store/xx7cm72qy2c0643cm1ipngd87aqwkcdp-glibc-2.40-66/lib/libc.so.6+0x2a4d7) (BuildId: cddea92d6cba8333be952b5a02fd47d61054c5ab)
#17 0x7ffff7a2a59a in __libc_start_main@GLIBC_2.2.5 (/nix/store/xx7cm72qy2c0643cm1ipngd87aqwkcdp-glibc-2.40-66/lib/libc.so.6+0x2a59a) (BuildId: cddea92d6cba8333be952b5a02fd47d61054c5ab)
#18 0x5555555f0934 in _start (git+0x9c934)
The root cause of this memory leak is our use of `commit_list_append()`.
This function expects as parameters the item to append and the _tail_ of
the list to append. This tail will then be overwritten with the new tail
of the list so that it can be used in subsequent calls. But we call it
with `commit_list_append(parent->item, &stack)`, so we end up losing
everything but the new item.
This issue only surfaces when counting merge commits. Next to being a
memory leak, it also shows that we're in fact miscounting as we only
respect children of the last parent. All previous parents are discarded,
so their children will be disregarded unless they are hit via another
reference.
While crafting a test case for the issue I was puzzled that I couldn't
establish the proper border at which the auto-condition would be
fulfilled. As it turns out, there's another bug: if an object is at the
tip of any reference we don't mark it as seen. Consequently, if it is
reachable via any other reference, we'd count that object twice.
Fix both of these bugs so that we properly count objects without leaking
any memory.
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
gitgitgadget bot
pushed a commit
that referenced
this pull request
Dec 11, 2025
It is possible to hit a memory leak when reading data from a submodule
via git-grep(1):
Direct leak of 192 byte(s) in 1 object(s) allocated from:
#0 0x55555562e726 in calloc (git+0xda726)
#1 0x555555964734 in xcalloc ../wrapper.c:154:8
#2 0x555555835136 in load_multi_pack_index_one ../midx.c:135:2
#3 0x555555834fd6 in load_multi_pack_index ../midx.c:382:6
#4 0x5555558365b6 in prepare_multi_pack_index_one ../midx.c:716:17
#5 0x55555586c605 in packfile_store_prepare ../packfile.c:1103:3
#6 0x55555586c90c in packfile_store_reprepare ../packfile.c:1118:2
#7 0x5555558546b3 in odb_reprepare ../odb.c:1106:2
#8 0x5555558539e4 in do_oid_object_info_extended ../odb.c:715:4
#9 0x5555558533d1 in odb_read_object_info_extended ../odb.c:862:8
#10 0x5555558540bd in odb_read_object ../odb.c:920:6
#11 0x55555580a330 in grep_source_load_oid ../grep.c:1934:12
#12 0x55555580a13a in grep_source_load ../grep.c:1986:10
#13 0x555555809103 in grep_source_is_binary ../grep.c:2014:7
#14 0x555555807574 in grep_source_1 ../grep.c:1625:8
#15 0x555555807322 in grep_source ../grep.c:1837:10
#16 0x5555556a5c58 in run ../builtin/grep.c:208:10
#17 0x55555562bb42 in void* ThreadStartFunc<false>(void*) lsan_interceptors.cpp.o
#18 0x7ffff7a9a979 in start_thread (/nix/store/xx7cm72qy2c0643cm1ipngd87aqwkcdp-glibc-2.40-66/lib/libc.so.6+0x9a979) (BuildId: cddea92d6cba8333be952b5a02fd47d61054c5ab)
#19 0x7ffff7b22d2b in __GI___clone3 (/nix/store/xx7cm72qy2c0643cm1ipngd87aqwkcdp-glibc-2.40-66/lib/libc.so.6+0x122d2b) (BuildId: cddea92d6cba8333be952b5a02fd47d61054c5ab)
The root caues of this leak is the way we set up and release the
submodule:
1. We use `repo_submodule_init()` to initialize a new repository. This
repository is stored in `repos_to_free`.
2. We now read data from the submodule repository.
3. We then call `repo_clear()` on the submodule repositories.
4. `repo_clear()` calls `odb_free()`.
5. `odb_free()` calls `odb_free_sources()` followed by `odb_close()`.
The issue here is the 5th step: we call `odb_free_sources()` _before_ we
call `odb_close()`. But `odb_free_sources()` already frees all sources,
so the logic that closes them in `odb_close()` now becomes a no-op. As a
consequence, we never explicitly close sources at all.
Fix the leak by closing the store before we free the sources.
Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
No description provided.