diff mbox series

[RFC] sierra: avoid trailing bytes leading to garbage parsing

Message ID 20220217103057.10184-1-oneukum@suse.com (mailing list archive)
State RFC
Delegated to: Netdev Maintainers
Headers show
Series [RFC] sierra: avoid trailing bytes leading to garbage parsing | expand

Checks

Context Check Description
netdev/tree_selection success Guessed tree name to be net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/cc_maintainers warning 2 maintainers not CCed: davem@davemloft.net kuba@kernel.org
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 9 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Oliver Neukum Feb. 17, 2022, 10:30 a.m. UTC
The driver's main loop isn't ready for a device sending
some trailing bytes as it tests for an exact match between
package and accumulated frames.
We would parse some garbage from the heap and follow its
pointers.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/net/usb/smsc75xx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/net/usb/smsc75xx.c b/drivers/net/usb/smsc75xx.c
index 95de452ff4da..649e43b4df4f 100644
--- a/drivers/net/usb/smsc75xx.c
+++ b/drivers/net/usb/smsc75xx.c
@@ -2183,7 +2183,8 @@  static int smsc75xx_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 	if (skb->len < dev->net->hard_header_len)
 		return 0;
 
-	while (skb->len > 0) {
+	/* at least two u32 must be left to go on */
+	while (skb->len > 4 + 4) {
 		u32 rx_cmd_a, rx_cmd_b, align_count, size;
 		struct sk_buff *ax_skb;
 		unsigned char *packet;