cifs: Fix buffer overflow when parsing NFS reparse points
commit e2a8910af01653c1c268984855629d71fb81f404 upstream.
ReparseDataLength is sum of the InodeType size and DataBuffer size.
So to get DataBuffer size it is needed to subtract InodeType's size from
ReparseDataLength.
Function cifs_strndup_from_utf16() is currentlly accessing buf->DataBuffer
at position after the end of the buffer because it does not subtract
InodeType size from the length. Fix this problem and correctly subtract
variable len.
Member InodeType is present only when reparse buffer is large enough. Check
for ReparseDataLength before accessing InodeType to prevent another invalid
memory access.
Major and minor rdev values are present also only when reparse buffer is
large enough. Check for reparse buffer size before calling reparse_mkdev().
BUG=b/375751811
TEST=presubmit
RELEASE_NOTE=Fixed CVE-2024-49996 in the Linux kernel.
cos-patch: security-high
Fixes: d5ecebc4900d ("smb3: Allow query of symlinks stored as reparse points")
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Change-Id: I5cbc6fc4cba38913a5d8ecc4f332d7b08cd05a8e
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
[use variable name symlink_buf, the other buf->InodeType accesses are
not used in current version so skip]
Signed-off-by: Mahmoud Adam <mngyadam@amazon.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kernel CVE Triage Automation <cloud-image-kernel-cve-triage-automation@prod.google.com>
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/90695
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Arnav Kansal <rnv@google.com>
Reviewed-by: Michael Kochera <kochera@google.com>
1 file changed
