From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leon Romanovsky Subject: Re: WARNING in rds_message_alloc_sgs Date: Wed, 31 Oct 2018 08:42:20 +0200 Message-ID: <20181031064220.GN3974@mtr-leonro.mtl.com> References: <0000000000003c6b7b0579772ff3@google.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Q8BnQc91gJZX4vDc" Cc: syzbot , linux-rdma@vger.kernel.org, netdev@vger.kernel.org, rds-devel@oss.oracle.com, syzkaller-bugs@googlegroups.com, davem@davemloft.net, linux-kernel@vger.kernel.org To: Santosh Shilimkar Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org --Q8BnQc91gJZX4vDc Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Oct 30, 2018 at 12:38:02PM -0700, Santosh Shilimkar wrote: > On 10/30/2018 12:28 PM, syzbot wrote: > > Hello, > > > > syzbot found the following crash on: > > > > HEAD commit:=A0=A0=A0 6201f31a39f8 Add linux-next specific files for 20= 181030 > > git tree:=A0=A0=A0=A0=A0=A0 linux-next > > console output: https://syzkaller.appspot.com/x/log.txt?x=3D1397d06d400= 000 > > kernel config:=A0 https://syzkaller.appspot.com/x/.config?x=3D2a22859d8= 70756c1 > > dashboard link: > > https://syzkaller.appspot.com/bug?extid=3D26de17458aeda9d305d8 > > compiler:=A0=A0=A0=A0=A0=A0 gcc (GCC) 8.0.1 20180413 (experimental) > > syz repro:=A0=A0=A0=A0=A0 https://syzkaller.appspot.com/x/repro.syz?x= =3D10bb52eb400000 > > C reproducer:=A0=A0 https://syzkaller.appspot.com/x/repro.c?x=3D118bdfc= 5400000 > > > > IMPORTANT: if you fix the bug, please add the following tag to the comm= it: > > Reported-by: syzbot+26de17458aeda9d305d8@syzkaller.appspotmail.com > > > > 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 !! Please don't forget to remove user triggered WARN_ON. https://lwn.net/Articles/769365/ "Greg Kroah-Hartman raised the problem of core kernel API code that will use WARN_ON_ONCE() to complain about bad usage; that will not generate the desired result if WARN_ON_ONCE() is configured to crash the machine. He was told that the code should just call pr_warn() instead, and that the called function should return an error in such situations. It was generally agreed that any WARN_ON() or WARN_ON_ONCE() calls that can be triggered from user space need to be fixed." Thanks > > Regards, > Santosh --Q8BnQc91gJZX4vDc Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIcBAEBAgAGBQJb2U7MAAoJEORje4g2clinySoP/1M2x8wQN60bkPszYgFYoOqD rouJticqrcknoxCPIzwHEMtzdEMvEnEKD5980BIHank13TJ3MIb9NIhDGZ3N9lVY Is5x9YJRsKLouY68Ui7VDNsJ0DPYO5ylfvyyp7eSUyf0hGbRZ3axqeoLQFCo2S6e 4VOYlYJlLJ+tEueEyEY/gnD6yaVlYfXijDIZzd/olDxDIx6eGfPg2kscNqDD/M6Z Js4scqLtMGqsjYn+yR50e8TFVKssLdSDhY7ADl0DDzPiZZHpqRVHRwrGu9XO3O8e XUNCGBlzqA0O+ltbvgLRIBlQ1fIrBOo0q/qAvp8dPQs/k+VnQe6AzHlLGMaE9DuL qlS536JxC3f/WsOc+sk7e/zMphiH44crLzZ6LI56PVdCKANdAAN47lOr/HroOh5v PFEuFUALrOSo4Yl6Xsoc/6L+qdVZDB4JtbrDUvuzmAkTz0cQKSrWH3JN+IYQErzZ LUHk3Pf1/r81/DxkirokTfHpUSKiruDvaAFs3Q925xxNGUjU5axj8X10c7sQNchD lkRhT3TIa5KCtOK4m7fW53j24WUe6NtBbym0/bhoC0fX4gekF5bp3AqY0I7WF+w6 gDd/etlAfYlK4yTQbVKWbHTKEmMxBsEFDUJSvsn9HrgeWEZdbfVOV6CfPj0qz5nu EeprTD0XCeG4M0bWxkNU =uvwi -----END PGP SIGNATURE----- --Q8BnQc91gJZX4vDc--