Re: [PATCH] net: nfc: nci: fix for UBSAN: shift-out-of-bounds in nci_activate_target

[Krzysztof Kozlowski]

On 19/04/2023 03:16, Anup Sharma wrote:
> syzbot found  UBSAN: shift-out-of-bounds in nci_activate_target [1],
> when nci_target->supported_protocols is bigger than UNIT_MAX,
> where supported_protocols is unsigned 32-bit interger type.
> 
> 32 is the maximum allowed for supported_protocols. Added a check
> for it. 
> 
> [1] UBSAN: shift-out-of-bounds in net/nfc/nci/core.c:912:45
> shift exponent 4294967071 is too large for 32-bit type 'int'
> Call Trace:
>  <TASK>
>  __dump_stack lib/dump_stack.c:88 [inline]
>  dump_stack_lvl+0x136/0x150 lib/dump_stack.c:106
>  ubsan_epilogue lib/ubsan.c:217 [inline]
>  __ubsan_handle_shift_out_of_bounds+0x221/0x5a0 lib/ubsan.c:387
>  nci_activate_target.cold+0x1a/0x1f net/nfc/nci/core.c:912
>  nfc_activate_target+0x1f8/0x4c0 net/nfc/core.c:420
>  nfc_genl_activate_target+0x1f3/0x290 net/nfc/netlink.c:900
>  genl_family_rcv_msg_doit.isra.0+0x1e6/0x2d0 net/netlink/genetlink.c:968
>  genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline]
> 
> Reported-by: syzbot+0839b78e119aae1fec78@xxxxxxxxxxxxxxxxxxxxxxxxx
> Link: https://syzkaller.appspot.com/bug?id=19cf2724120ef8c51c8d2566df0cc34617188433
> 
> Signed-off-by: anupsharma <anupnewsmail@xxxxxxxxx>

Also, no blank lines between tags.

Best regards,
Krzysztof