Bug 266885
| Summary: | [FUSEFS] fcntl(F_GETLK) overwrites flock->l_pid even if unlocked | ||
|---|---|---|---|
| Product: | Base System | Reporter: | John Millikin <jmillikin> |
| Component: | kern | Assignee: | Alan Somers <asomers> |
| Status: | Closed FIXED | ||
| Severity: | Affects Some People | CC: | asomers, emaste, grahamperrin |
| Priority: | --- | Flags: | asomers:
mfc-stable13+
asomers: mfc-stable12+ |
| Version: | CURRENT | ||
| Hardware: | Any | ||
| OS: | Any | ||
| URL: | https://reviews.freebsd.org/D36905 | ||
A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=46fcf947c6c8db1e1ceb3cbd75b69d1d1e494929 commit 46fcf947c6c8db1e1ceb3cbd75b69d1d1e494929 Author: Alan Somers <asomers@FreeBSD.org> AuthorDate: 2022-10-07 14:46:22 +0000 Commit: Alan Somers <asomers@FreeBSD.org> CommitDate: 2022-10-07 15:09:21 +0000 fusefs: during F_GETLK, don't change l_pid if no lock is found PR: 266885 MFC after: 2 weeks Submitted by: John Millikin <jmillikin@gmail.com> Sponsored by: Axcient Reviewed by: emaste Differential Revision: https://reviews.freebsd.org/D36905 sys/fs/fuse/fuse_vnops.c | 2 +- tests/sys/fs/fusefs/locks.cc | 16 ++++++++++++++-- 2 files changed, 15 insertions(+), 3 deletions(-) A commit in branch stable/12 references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=274f5099706f33bf69fa29546dd6c94fde8eb001 commit 274f5099706f33bf69fa29546dd6c94fde8eb001 Author: Alan Somers <asomers@FreeBSD.org> AuthorDate: 2022-10-07 14:46:22 +0000 Commit: Alan Somers <asomers@FreeBSD.org> CommitDate: 2022-10-19 01:13:55 +0000 fusefs: during F_GETLK, don't change l_pid if no lock is found PR: 266885 Submitted by: John Millikin <jmillikin@gmail.com> Sponsored by: Axcient Reviewed by: emaste Differential Revision: https://reviews.freebsd.org/D36905 (cherry picked from commit 46fcf947c6c8db1e1ceb3cbd75b69d1d1e494929) sys/fs/fuse/fuse_vnops.c | 2 +- tests/sys/fs/fusefs/locks.cc | 16 ++++++++++++++-- 2 files changed, 15 insertions(+), 3 deletions(-) Triage: * assign to committer resolving * asomers@, attention to flags? A commit in branch stable/13 references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=ab7955aec728c03d9388aff7b03ca748c69a0eb4 commit ab7955aec728c03d9388aff7b03ca748c69a0eb4 Author: Alan Somers <asomers@FreeBSD.org> AuthorDate: 2022-10-07 14:46:22 +0000 Commit: Alan Somers <asomers@FreeBSD.org> CommitDate: 2022-10-31 00:51:30 +0000 fusefs: during F_GETLK, don't change l_pid if no lock is found PR: 266885 Submitted by: John Millikin <jmillikin@gmail.com> Sponsored by: Axcient Reviewed by: emaste Differential Revision: https://reviews.freebsd.org/D36905 (cherry picked from commit 46fcf947c6c8db1e1ceb3cbd75b69d1d1e494929) sys/fs/fuse/fuse_vnops.c | 2 +- tests/sys/fs/fusefs/locks.cc | 16 ++++++++++++++-- 2 files changed, 15 insertions(+), 3 deletions(-) |
The documentation for fcntl(F_GETLK) says: If no lock is found that would prevent this lock from being created, the structure is left unchanged by this system call except for the lock type which is set to F_UNLCK. However, the code is currently overwriting the flock structure's `l_pid` field: /* sys/fs/fuse/fuse_vnops.c :: fuse_vnop_advlock() */ if (err == 0 && op == FUSE_GETLK) { flo = fdi.answ; fl->l_type = flo->lk.type; fl->l_pid = flo->lk.pid; /* <- here */ if (flo->lk.type != F_UNLCK) { fl->l_start = flo->lk.start; I think that assignment should be moved down a line, into the `!= F_UNLCK` branch.