imrcpan/erofs-linux
1
0 Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git synced 2026-11-09 02:51:11 +01:00
Code Issues Packages Projects Releases Wiki Activity

AX.25: Fix out-of-bounds read in ax25_connect()

Browse Source 
Checks on `addr_len` and `fsa->fsa_ax25.sax25_ndigis` are insufficient.
ax25_connect() can go out of bounds when `fsa->fsa_ax25.sax25_ndigis`
equals to 7 or 8. Fix it.

This issue has been reported as a KMSAN uninit-value bug, because in such
a case, ax25_connect() reaches into the uninitialized portion of the
`struct sockaddr_storage` statically allocated in __sys_connect().

It is safe to remove `fsa->fsa_ax25.sax25_ndigis > AX25_MAX_DIGIS` because
`addr_len` is guaranteed to be less than or equal to
`sizeof(struct full_sockaddr_ax25)`.

Reported-by: [email protected]
Link: https://syzkaller.appspot.com/bug?id=55ef9d629f3b3d7d70b69558015b63b48d01af66
Signed-off-by: Peilin Ye <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
This commit is contained in:
Peilin Ye authored and David S. Miller committed 2020-07-22 17:56:40 -07:00
1 parent 26cb7085c8
commit 2f2a7ffad5
1 file changed
+3 -1
Download Patch File Download Diff File Expand all files Collapse all files
net/ax25/af_ax25.c
+3 -1
View File
@@ -1187,7 +1187,9 @@ static int __must_check ax25_connect(struct socket *sock,
if (addr_len > sizeof(struct sockaddr_ax25) &&
fsa->fsa_ax25.sax25_ndigis != 0) {
/* Valid number of digipeaters ? */
if (fsa->fsa_ax25.sax25_ndigis < 1 || fsa->fsa_ax25.sax25_ndigis > AX25_MAX_DIGIS) {
if (fsa->fsa_ax25.sax25_ndigis < 1 ||
addr_len < sizeof(struct sockaddr_ax25) +
sizeof(ax25_address) * fsa->fsa_ax25.sax25_ndigis) {
err = -EINVAL;
goto out_release;
}