Re: WARNING in rds_message_alloc_sgs

From: Santosh Shilimkar
Date: Tue Oct 30 2018 - 15:38:21 EST

On 10/30/2018 12:28 PM, syzbot wrote:

syzbot found the following crash on:

HEAD commit:ÂÂÂ 6201f31a39f8 Add linux-next specific files for 20181030
git tree:ÂÂÂÂÂÂ linux-next
console output:
kernel config:Â
dashboard link:
compiler:ÂÂÂÂÂÂ gcc (GCC) 8.0.1 20180413 (experimental)
syz repro:ÂÂÂÂÂ
C reproducer:ÂÂ

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+26de17458aeda9d305d8@xxxxxxxxxxxxxxxxxxxxxxxxx

WARNING: CPU: 0 PID: 19789 at net/rds/message.c:316 rds_message_alloc_sgs+0x10c/0x160 net/rds/message.c:316
Kernel panic - not syncing: panic_on_warn set ...
Looks like this kernel build has panic on warn enabled which
triggers panic for " WARN_ON(!nr_pages)" case. Will look into
it. Thanks !!