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0b63c0e01f
Syzkaller is able to provoke null-ptr-dereference in ocfs2_xa_remove():
[ 57.319872] (a.out,1161,7):ocfs2_xa_remove:2028 ERROR: status = -12
[ 57.320420] (a.out,1161,7):ocfs2_xa_cleanup_value_truncate:1999 ERROR: Partial truncate while removing xattr overlay.upper. Leaking 1 clusters and removing the entry
[ 57.321727] BUG: kernel NULL pointer dereference, address: 0000000000000004
[...]
[ 57.325727] RIP: 0010:ocfs2_xa_block_wipe_namevalue+0x2a/0xc0
[...]
[ 57.331328] Call Trace:
[ 57.331477] <TASK>
[...]
[ 57.333511] ? do_user_addr_fault+0x3e5/0x740
[ 57.333778] ? exc_page_fault+0x70/0x170
[ 57.334016] ? asm_exc_page_fault+0x2b/0x30
[ 57.334263] ? __pfx_ocfs2_xa_block_wipe_namevalue+0x10/0x10
[ 57.334596] ? ocfs2_xa_block_wipe_namevalue+0x2a/0xc0
[ 57.334913] ocfs2_xa_remove_entry+0x23/0xc0
[ 57.335164] ocfs2_xa_set+0x704/0xcf0
[ 57.335381] ? _raw_spin_unlock+0x1a/0x40
[ 57.335620] ? ocfs2_inode_cache_unlock+0x16/0x20
[ 57.335915] ? trace_preempt_on+0x1e/0x70
[ 57.336153] ? start_this_handle+0x16c/0x500
[ 57.336410] ? preempt_count_sub+0x50/0x80
[ 57.336656] ? _raw_read_unlock+0x20/0x40
[ 57.336906] ? start_this_handle+0x16c/0x500
[ 57.337162] ocfs2_xattr_block_set+0xa6/0x1e0
[ 57.337424] __ocfs2_xattr_set_handle+0x1fd/0x5d0
[ 57.337706] ? ocfs2_start_trans+0x13d/0x290
[ 57.337971] ocfs2_xattr_set+0xb13/0xfb0
[ 57.338207] ? dput+0x46/0x1c0
[ 57.338393] ocfs2_xattr_trusted_set+0x28/0x30
[ 57.338665] ? ocfs2_xattr_trusted_set+0x28/0x30
[ 57.338948] __vfs_removexattr+0x92/0xc0
[ 57.339182] __vfs_removexattr_locked+0xd5/0x190
[ 57.339456] ? preempt_count_sub+0x50/0x80
[ 57.339705] vfs_removexattr+0x5f/0x100
[...]
Reproducer uses faultinject facility to fail ocfs2_xa_remove() ->
ocfs2_xa_value_truncate() with -ENOMEM.
In this case the comment mentions that we can return 0 if
ocfs2_xa_cleanup_value_truncate() is going to wipe the entry
anyway. But the following 'rc' check is wrong and execution flow do
'ocfs2_xa_remove_entry(loc);' twice:
* 1st: in ocfs2_xa_cleanup_value_truncate();
* 2nd: returning back to ocfs2_xa_remove() instead of going to 'out'.
Fix this by skipping the 2nd removal of the same entry and making
syzkaller repro happy.
Link: https://lkml.kernel.org/r/20241103193845.2940988-1-andrew.kanner@gmail.com
Fixes:
|
||
|---|---|---|
| .. | ||
| cluster | ||
| dlm | ||
| dlmfs | ||
| acl.c | ||
| acl.h | ||
| alloc.c | ||
| alloc.h | ||
| aops.c | ||
| aops.h | ||
| blockcheck.c | ||
| blockcheck.h | ||
| buffer_head_io.c | ||
| buffer_head_io.h | ||
| dcache.c | ||
| dcache.h | ||
| dir.c | ||
| dir.h | ||
| dlmglue.c | ||
| dlmglue.h | ||
| export.c | ||
| export.h | ||
| extent_map.c | ||
| extent_map.h | ||
| file.c | ||
| file.h | ||
| filecheck.c | ||
| filecheck.h | ||
| heartbeat.c | ||
| heartbeat.h | ||
| inode.c | ||
| inode.h | ||
| ioctl.c | ||
| ioctl.h | ||
| journal.c | ||
| journal.h | ||
| Kconfig | ||
| localalloc.c | ||
| localalloc.h | ||
| locks.c | ||
| locks.h | ||
| Makefile | ||
| mmap.c | ||
| mmap.h | ||
| move_extents.c | ||
| move_extents.h | ||
| namei.c | ||
| namei.h | ||
| ocfs1_fs_compat.h | ||
| ocfs2_fs.h | ||
| ocfs2_ioctl.h | ||
| ocfs2_lockid.h | ||
| ocfs2_lockingver.h | ||
| ocfs2_trace.h | ||
| ocfs2.h | ||
| quota_global.c | ||
| quota_local.c | ||
| quota.h | ||
| refcounttree.c | ||
| refcounttree.h | ||
| reservations.c | ||
| reservations.h | ||
| resize.c | ||
| resize.h | ||
| slot_map.c | ||
| slot_map.h | ||
| stack_o2cb.c | ||
| stack_user.c | ||
| stackglue.c | ||
| stackglue.h | ||
| suballoc.c | ||
| suballoc.h | ||
| super.c | ||
| super.h | ||
| symlink.c | ||
| symlink.h | ||
| sysfile.c | ||
| sysfile.h | ||
| uptodate.c | ||
| uptodate.h | ||
| xattr.c | ||
| xattr.h | ||