As reported:
This problem was discovered when doing BGP traffic with the TCP MD5 option
activated, where the following call chain caused a crash:
* tcp_v4_rcv
* tcp_v4_timewait_ack
* tcp_v4_send_ack -> follow stack variable rep.th
* tcp_v4_md5_hash_hdr
* tcp_md5_hash_header
* sg_init_one
* sg_set_buf
* virt_to_page
I noticed that tcp_v4_send_reset uses a similar stack variable and
also calls tcp_v4_md5_hash_hdr, so it has the same problem.
The networking core can indirectly call virt_to_phys() on stack
addresses, if this is done from PID 0, the stack will usually be in
CKSEG0, so virt_to_phys() needs to work there as well
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: Jiang Liu <liuj97@gmail.com>
Cc: eunb.song@samsung.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/5220/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
49c426ba44