Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

wifi: mt7601u: fix an integer underflow

Fix an integer underflow that leads to a null pointer dereference in 'mt7601u_rx_skb_from_seg()'. The variable 'dma_len' in the URB packet could be manipulated, which could trigger an integer underflow of 'seg_len' in 'mt7601u_rx_process_seg()'. This underflow subsequently causes the 'bad_frame' checks in 'mt7601u_rx_skb_from_seg()' to be bypassed, eventually leading to a dereference of the pointer 'p', which is a null pointer.

Ensure that 'dma_len' is greater than 'min_seg_len'.

Found by a modified version of syzkaller.

KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 PID: 12 Comm: ksoftirqd/0 Tainted: G W O 5.14.0+ #139 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 RIP: 0010:skb_add_rx_frag+0x143/0x370 Code: e2 07 83 c2 03 38 ca 7c 08 84 c9 0f 85 86 01 00 00 4c 8d 7d 08 44 89 68 08 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 cd 01 00 00 48 8b 45 08 a8 01 0f 85 3d 01 00 00 RSP: 0018:ffffc900000cfc90 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff888115520dc0 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffff8881118430c0 RDI: ffff8881118430f8 RBP: 0000000000000000 R08: 0000000000000e09 R09: 0000000000000010 R10: ffff888111843017 R11: ffffed1022308602 R12: 0000000000000000 R13: 0000000000000e09 R14: 0000000000000010 R15: 000…