diff options
| author | Darrick J. Wong <djwong@kernel.org> | 2026-01-23 20:27:39 +0300 |
|---|---|---|
| committer | Darrick J. Wong <djwong@kernel.org> | 2026-01-24 19:46:41 +0300 |
| commit | 1c253e11225bc5167217897885b85093e17c2217 (patch) | |
| tree | c81db369e80dd9778bba4d0092c963cf43bda813 | |
| parent | ca27313fb3f23e4ac18532ede4ec1c7cc5814c4a (diff) | |
| download | linux-1c253e11225bc5167217897885b85093e17c2217.tar.xz | |
xfs: fix UAF in xchk_btree_check_block_owner
We cannot dereference bs->cur when trying to determine if bs->cur
aliases bs->sc->sa.{bno,rmap}_cur after the latter has been freed.
Fix this by sampling before type before any freeing could happen.
The correct temporal ordering was broken when we removed xfs_btnum_t.
Cc: r772577952@gmail.com
Cc: <stable@vger.kernel.org> # v6.9
Fixes: ec793e690f801d ("xfs: remove xfs_btnum_t")
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Jiaming Zhang <r772577952@gmail.com>
| -rw-r--r-- | fs/xfs/scrub/btree.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/xfs/scrub/btree.c b/fs/xfs/scrub/btree.c index 40f36db9f07d..1089b1f4c5df 100644 --- a/fs/xfs/scrub/btree.c +++ b/fs/xfs/scrub/btree.c @@ -372,12 +372,15 @@ xchk_btree_check_block_owner( { xfs_agnumber_t agno; xfs_agblock_t agbno; + bool is_bnobt, is_rmapbt; bool init_sa; int error = 0; if (!bs->cur) return 0; + is_bnobt = xfs_btree_is_bno(bs->cur->bc_ops); + is_rmapbt = xfs_btree_is_rmap(bs->cur->bc_ops); agno = xfs_daddr_to_agno(bs->cur->bc_mp, daddr); agbno = xfs_daddr_to_agbno(bs->cur->bc_mp, daddr); @@ -400,11 +403,11 @@ xchk_btree_check_block_owner( * have to nullify it (to shut down further block owner checks) if * self-xref encounters problems. */ - if (!bs->sc->sa.bno_cur && xfs_btree_is_bno(bs->cur->bc_ops)) + if (!bs->sc->sa.bno_cur && is_bnobt) bs->cur = NULL; xchk_xref_is_only_owned_by(bs->sc, agbno, 1, bs->oinfo); - if (!bs->sc->sa.rmap_cur && xfs_btree_is_rmap(bs->cur->bc_ops)) + if (!bs->sc->sa.rmap_cur && is_rmapbt) bs->cur = NULL; out_free: |