Commit afcc9adf authored by lei lu's avatar lei lu Committed by Long Li
Browse files

xfs: add bounds checking to xlog_recover_process_data

mainline inclusion
from mainline-v6.10-rc2
commit fb63435b7c7dc112b1ae1baea5486e0a6e27b196
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAG8QA
CVE: CVE-2024-41014

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fb63435b7c7dc112b1ae1baea5486e0a6e27b196



--------------------------------

There is a lack of verification of the space occupied by fixed members
of xlog_op_header in the xlog_recover_process_data.

We can create a crafted image to trigger an out of bounds read by
following these steps:
    1) Mount an image of xfs, and do some file operations to leave records
    2) Before umounting, copy the image for subsequent steps to simulate
       abnormal exit. Because umount will ensure that tail_blk and
       head_blk are the same, which will result in the inability to enter
       xlog_recover_process_data
    3) Write a tool to parse and modify the copied image in step 2
    4) Make the end of the xlog_op_header entries only 1 byte away from
       xlog_rec_header->h_size
    5) xlog_rec_header->h_num_logops++
    6) Modify xlog_rec_header->h_crc

Fix:
Add a check to make sure there is sufficient space to access fixed members
of xlog_op_header.

Signed-off-by: default avatarlei lu <llfamsec@gmail.com>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarChandan Babu R <chandanbabu@kernel.org>
Signed-off-by: default avatarLong Li <leo.lilong@huawei.com>
parent 39d17121
Loading
Loading
Loading
Loading
+4 −1
Original line number Diff line number Diff line
@@ -2438,7 +2438,10 @@ xlog_recover_process_data(

		ohead = (struct xlog_op_header *)dp;
		dp += sizeof(*ohead);
		ASSERT(dp <= end);
		if (dp > end) {
			xfs_warn(log->l_mp, "%s: op header overrun", __func__);
			return -EFSCORRUPTED;
		}

		/* errors will abort recovery */
		error = xlog_recover_process_ophdr(log, rhash, rhead, ohead,