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| author | Szymon Wilczek <swilczek.lx@gmail.com> | 2025-12-27 15:43:07 +0100 |
|---|---|---|
| committer | Konstantin Komarov <almaz.alexandrovich@paragon-software.com> | 2026-01-15 05:57:48 +0100 |
| commit | 08ce2fee1b869ecbfbd94e0eb2630e52203a2e03 (patch) | |
| tree | 9dbb6de88001b1745c7b0615a74bb282d9340335 /rust/alloc/collections/git@git.tavy.me:linux.git | |
| parent | 099ef9ab9203dff327f2d61e44773f9acbc01f13 (diff) | |
ntfs3: fix circular locking dependency in run_unpack_ex
Syzbot reported a circular locking dependency between wnd->rw_lock
(sbi->used.bitmap) and ni->file.run_lock.
The deadlock scenario:
1. ntfs_extend_mft() takes ni->file.run_lock then wnd->rw_lock.
2. run_unpack_ex() takes wnd->rw_lock then tries to acquire
ni->file.run_lock inside ntfs_refresh_zone().
This creates an AB-BA deadlock.
Fix this by using down_read_trylock() instead of down_read() when
acquiring run_lock in run_unpack_ex(). If the lock is contended,
skip ntfs_refresh_zone() - the MFT zone will be refreshed on the
next MFT operation. This breaks the circular dependency since we
never block waiting for run_lock while holding wnd->rw_lock.
Reported-by: syzbot+d27edf9f96ae85939222@syzkaller.appspotmail.com
Tested-by: syzbot+d27edf9f96ae85939222@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=d27edf9f96ae85939222
Signed-off-by: Szymon Wilczek <swilczek.lx@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Diffstat (limited to 'rust/alloc/collections/git@git.tavy.me:linux.git')
0 files changed, 0 insertions, 0 deletions