Introduce preliminary bblob fsck support#4
Open
ulrik-s wants to merge 20 commits into
Open
Conversation
ulrik-s
pushed a commit
that referenced
this pull request
Sep 11, 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
git#11 0x0000007e8a35 in cmd_main ../git.c:953
git#12 0x000000441e8f in main ../common-main.c:9
git#13 0x7ff9754115f4 in __libc_start_call_main (/lib64/libc.so.6+0x35f4)
git#14 0x7ff9754116a7 in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x36a7)
git#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 <peff@peff.net>
Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
ulrik-s
pushed a commit
that referenced
this pull request
Oct 10, 2025
The fill_packs_from_midx() method was refactored in fcb2205 (midx: implement support for writing incremental MIDX chains, 2024-08-06) to allow for preferred packfiles and incremental multi-pack-indexes. However, this led to some conditions that can cause improperly initialized memory in the context's list of packfiles. The conditions caring about the preferred pack name or the incremental flag are currently necessary to load a packfile. But the context is still being populated with pack_info structs based on the packfile array for the existing multi-pack-index even if prepare_midx_pack() isn't called. Add a new test that breaks under --stress when compiled with SANITIZE=address. The chosen number of 100 packfiles was selected to get the --stress output to fail about 50% of the time, while 50 packfiles could not get a failure in most --stress runs. The test case is marked as EXPENSIVE not only because of the number of packfiles it creates, but because some CI environments were reporting errors during the test that I could not reproduce, specifically around being unable to open the packfiles or their pack-indexes. When it fails under SANITIZE=address, it provides the following error: AddressSanitizer:DEADLYSIGNAL ================================================================= ==3263517==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000027 ==3263517==The signal is caused by a READ memory access. ==3263517==Hint: address points to the zero page. #0 0x562d5d82d1fb in close_pack_windows packfile.c:299 #1 0x562d5d82d3ab in close_pack packfile.c:354 #2 0x562d5d7bfdb4 in write_midx_internal midx-write.c:1490 #3 0x562d5d7c7aec in midx_repack midx-write.c:1795 #4 0x562d5d46fff6 in cmd_multi_pack_index builtin/multi-pack-index.c:305 ... This failure stack trace is disconnected from the real fix because the bad pointers are accessed later when closing the packfiles from the context. There are a few different aspects to this fix that are worth noting: 1. We return to the previous behavior of fill_packs_from_midx to not rely on the incremental flag or existence of a preferred pack. 2. The behavior to scan all layers of an incremental midx is kept, so this is not a full revert of the change. 3. We skip allocating more room in the pack_info array if the pack fails prepare_midx_pack(). 4. The method has always returned 0 for success and 1 for failure, but the condition checking for error added a check for a negative result for failure, so that is now updated. 5. The call to open_pack_index() is removed, but this is needed later in the case of a preferred pack. That call is moved to immediately before its result is needed (checking for the object count). Signed-off-by: Derrick Stolee <stolee@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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.
Summary
full_bblob_verifygit repack --convert-to-bblobTesting
make -j2make -C t -j2(fails with "Error 2" despite log showing all 2600 tests passed)cd t && ./t1030-bblob.sh -vci/check-whitespace.sh HEAD^https://chatgpt.com/codex/tasks/task_e_685a68c0ced48324848d16a76cfafec9