Commit graph

8 commits

Author SHA1 Message Date
Andrew Kanner
940968132d ocfs2: remove entry once instead of null-ptr-dereference in ocfs2_xa_remove()
commit 0b63c0e01fba40e3992bc627272ec7b618ccaef7 upstream.

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: 399ff3a748cf ("ocfs2: Handle errors while setting external xattr values.")
Signed-off-by: Andrew Kanner <andrew.kanner@gmail.com>
Reported-by: syzbot+386ce9e60fa1b18aac5b@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/671e13ab.050a0220.2b8c0f.01d0.GAE@google.com/T/
Tested-by: syzbot+386ce9e60fa1b18aac5b@syzkaller.appspotmail.com
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-30 02:33:26 +01:00
Ksawlii
ea2eef284d Revert "ocfs2: add bounds checking to ocfs2_xattr_find_entry()"
This reverts commit 9f8e960daa.
2024-11-24 00:23:33 +01:00
Ksawlii
288d6adf78 Revert "ocfs2: strict bound check before memcmp in ocfs2_xattr_find_entry()"
This reverts commit e5a4f3990a.
2024-11-24 00:23:32 +01:00
Ksawlii
dfe3742af2 Revert "ocfs2: reserve space for inline xattr before attaching reflink tree"
This reverts commit 63e2db6c0b.
2024-11-24 00:23:03 +01:00
Gautham Ananthakrishna
63e2db6c0b ocfs2: reserve space for inline xattr before attaching reflink tree
commit 5ca60b86f57a4d9648f68418a725b3a7de2816b0 upstream.

One of our customers reported a crash and a corrupted ocfs2 filesystem.
The crash was due to the detection of corruption.  Upon troubleshooting,
the fsck -fn output showed the below corruption

[EXTENT_LIST_FREE] Extent list in owner 33080590 claims 230 as the next free chain record,
but fsck believes the largest valid value is 227.  Clamp the next record value? n

The stat output from the debugfs.ocfs2 showed the following corruption
where the "Next Free Rec:" had overshot the "Count:" in the root metadata
block.

        Inode: 33080590   Mode: 0640   Generation: 2619713622 (0x9c25a856)
        FS Generation: 904309833 (0x35e6ac49)
        CRC32: 00000000   ECC: 0000
        Type: Regular   Attr: 0x0   Flags: Valid
        Dynamic Features: (0x16) HasXattr InlineXattr Refcounted
        Extended Attributes Block: 0  Extended Attributes Inline Size: 256
        User: 0 (root)   Group: 0 (root)   Size: 281320357888
        Links: 1   Clusters: 141738
        ctime: 0x66911b56 0x316edcb8 -- Fri Jul 12 06:02:30.829349048 2024
        atime: 0x66911d6b 0x7f7a28d -- Fri Jul 12 06:11:23.133669517 2024
        mtime: 0x66911b56 0x12ed75d7 -- Fri Jul 12 06:02:30.317552087 2024
        dtime: 0x0 -- Wed Dec 31 17:00:00 1969
        Refcount Block: 2777346
        Last Extblk: 2886943   Orphan Slot: 0
        Sub Alloc Slot: 0   Sub Alloc Bit: 14
        Tree Depth: 1   Count: 227   Next Free Rec: 230
        ## Offset        Clusters       Block#
        0  0             2310           2776351
        1  2310          2139           2777375
        2  4449          1221           2778399
        3  5670          731            2779423
        4  6401          566            2780447
        .......          ....           .......
        .......          ....           .......

The issue was in the reflink workfow while reserving space for inline
xattr.  The problematic function is ocfs2_reflink_xattr_inline().  By the
time this function is called the reflink tree is already recreated at the
destination inode from the source inode.  At this point, this function
reserves space for inline xattrs at the destination inode without even
checking if there is space at the root metadata block.  It simply reduces
the l_count from 243 to 227 thereby making space of 256 bytes for inline
xattr whereas the inode already has extents beyond this index (in this
case up to 230), thereby causing corruption.

The fix for this is to reserve space for inline metadata at the destination
inode before the reflink tree gets recreated. The customer has verified the
fix.

Link: https://lkml.kernel.org/r/20240918063844.1830332-1-gautham.ananthakrishna@oracle.com
Fixes: ef962df057aa ("ocfs2: xattr: fix inlined xattr reflink")
Signed-off-by: Gautham Ananthakrishna <gautham.ananthakrishna@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-23 23:21:44 +01:00
Ferry Meng
e5a4f3990a ocfs2: strict bound check before memcmp in ocfs2_xattr_find_entry()
[ Upstream commit af77c4fc1871847b528d58b7fdafb4aa1f6a9262 ]

xattr in ocfs2 maybe 'non-indexed', which saved with additional space
requested.  It's better to check if the memory is out of bound before
memcmp, although this possibility mainly comes from crafted poisonous
images.

Link: https://lkml.kernel.org/r/20240520024024.1976129-2-joseph.qi@linux.alibaba.com
Signed-off-by: Ferry Meng <mengferry@linux.alibaba.com>
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reported-by: lei lu <llfamsec@gmail.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:21:15 +01:00
Ferry Meng
9f8e960daa ocfs2: add bounds checking to ocfs2_xattr_find_entry()
[ Upstream commit 9e3041fecdc8f78a5900c3aa51d3d756e73264d6 ]

Add a paranoia check to make sure it doesn't stray beyond valid memory
region containing ocfs2 xattr entries when scanning for a match.  It will
prevent out-of-bound access in case of crafted images.

Link: https://lkml.kernel.org/r/20240520024024.1976129-1-joseph.qi@linux.alibaba.com
Signed-off-by: Ferry Meng <mengferry@linux.alibaba.com>
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reported-by: lei lu <llfamsec@gmail.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: af77c4fc1871 ("ocfs2: strict bound check before memcmp in ocfs2_xattr_find_entry()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-23 23:21:15 +01:00
Gabriel2392
7ed7ee9edf Import A536BXXU9EXDC 2024-06-15 16:02:09 -03:00