Kernel/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2025-01-10 23:20:05 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

NET: mkiss: Fix panic

Browse Source 
If a USB-to-serial adapter is unplugged, the driver re-initializes, with
dev->hard_header_len and dev->addr_len set to zero, instead of the correct
values.  If then a packet is sent through the half-dead interface, the
kernel will panic due to running out of headroom in the skb when pushing
for the AX.25 headers resulting in this panic:

[<c0595468>] (skb_panic) from [<c0401f70>] (skb_push+0x4c/0x50)
[<c0401f70>] (skb_push) from [<bf0bdad4>] (ax25_hard_header+0x34/0xf4 [ax25])
[<bf0bdad4>] (ax25_hard_header [ax25]) from [<bf0d05d4>] (ax_header+0x38/0x40 [mkiss])
[<bf0d05d4>] (ax_header [mkiss]) from [<c041b584>] (neigh_compat_output+0x8c/0xd8)
[<c041b584>] (neigh_compat_output) from [<c043e7a8>] (ip_finish_output+0x2a0/0x914)
[<c043e7a8>] (ip_finish_output) from [<c043f948>] (ip_output+0xd8/0xf0)
[<c043f948>] (ip_output) from [<c043f04c>] (ip_local_out_sk+0x44/0x48)

This patch makes mkiss behave like the 6pack driver. 6pack does not
panic.  In 6pack.c sp_setup() (same function name here) the values for
dev->hard_header_len and dev->addr_len are set to the same values as in
my mkiss patch.

[ralf@linux-mips.org: Massages original submission to conform to the usual
standards for patch submissions.]

Signed-off-by: Thomas Osterried <thomas@osterried.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ralf Baechle 2017-02-09 14:12:11 +01:00 committed by David S. Miller
parent b85ea006b6
commit 7ba1b68903
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/net/hamradio/mkiss.c
View File

@ -648,8 +648,8 @@ static void ax_setup(struct net_device *dev)
{
/* Finish setting up the DEVICE info. */
dev->mtu = AX_MTU;
dev->hard_header_len = 0;
dev->addr_len = 0;
dev->hard_header_len = AX25_MAX_HEADER_LEN;
dev->addr_len = AX25_ADDR_LEN;
dev->type = ARPHRD_AX25;
dev->tx_queue_len = 10;
dev->header_ops = &ax25_header_ops;