xfs: fix intent use-after-free on abort
When an intent is aborted during it's initial commit through
xfs_defer_trans_abort(), there is a use after free. The current
report is for a RUI through this path in generic/388:
Freed by task 6274:
__kasan_slab_free+0x136/0x180
kmem_cache_free+0xe7/0x4b0
xfs_trans_free_items+0x198/0x2e0
__xfs_trans_commit+0x27f/0xcc0
xfs_trans_roll+0x17b/0x2a0
xfs_defer_trans_roll+0x6ad/0xe60
xfs_defer_finish+0x2a6/0x2140
xfs_alloc_file_space+0x53a/0xf90
xfs_file_fallocate+0x5c6/0xac0
vfs_fallocate+0x2f5/0x930
ioctl_preallocate+0x1dc/0x320
do_vfs_ioctl+0xfe4/0x1690
The problem is that the RUI has two active references - one in the
current transaction, and another held by the defer_ops structure
that is passed to the RUD (intent done) so that both the intent and
the intent done structures are freed on commit of the intent done.
Hence during abort, we need to release the intent item, because the
defer_ops reference is released separately via ->abort_intent
callback. Fix all the intent code to do this correctly.
Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
4 files changed