Messages in this thread | | | Date | Mon, 16 Oct 2017 14:41:47 +0100 | From | Mark Rutland <> | Subject | Re: WARNING in per_cpu_alloc |
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Hi,
On Sun, Oct 15, 2017 at 08:28:55AM -0400, Shankara Pailoor wrote: > Hi, > > We found the warning when fuzzing with Syzkaller on Linux 4-14-rc4. > > illegal size (32776) or align (8) for percpu allocation > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 22596 at mm/percpu.c:1365 pcpu_alloc+0x140/0x10f0 > Kernel panic - not syncing: panic_on_warn set ...
FWIW, this has already been reported upstream [1]. The suggested fix was to make pcpu_alloc suport __GFP_NOWARN, but I haven't had the chance to fix that up yet.
Thanks, Mark.
[1] https://lkml.kernel.org/r/20170928112727.GA11310@leverpostej
> CPU: 0 PID: 22596 Comm: syz-executor1 Not tainted 4.14.0-rc4 #1 > Hardware name: Google Google Compute Engine/Google Compute Engine, > BIOS Google 01/01/2011 > Call Trace: > dump_stack+0x115/0x1da > panic+0x1b4/0x3a7 > __warn+0x1c4/0x1d9 > report_bug+0x211/0x2d0 > fixup_bug+0x40/0x90 > do_trap+0x260/0x390 > do_error_trap+0x11c/0x350 > do_invalid_op+0x1b/0x20 > invalid_op+0x18/0x20 > RIP: 0010:pcpu_alloc+0x140/0x10f0 > RSP: 0018:ffff8800a752f6a8 EFLAGS: 00010286 > RAX: 0000000000000037 RBX: 0000000000000000 RCX: 0000000000000000 > RDX: 0000000000000037 RSI: ffffc90001a32000 RDI: ffffed0014ea5ec9 > RBP: ffff8800a752f920 R08: ffff8800a752ed98 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000008007 > R13: 0000000000000000 R14: ffff8800a752fec0 R15: 0000000000000008 > __alloc_percpu+0x24/0x30 > dev_map_alloc+0x68e/0xb70 > SyS_bpf+0xd25/0x4500 > entry_SYSCALL_64_fastpath+0x1f/0xbe > RIP: 0033:0x452349 > RSP: 002b:00007f8c38897be8 EFLAGS: 00000212 ORIG_RAX: 0000000000000141 > RAX: ffffffffffffffda RBX: 0000000000968000 RCX: 0000000000452349 > RDX: 000000000000001c RSI: 0000000020038000 RDI: 0000000000000000 > RBP: 0000000000000046 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f25a8 > R13: 00000000ffffffff R14: 0000000000968070 R15: 0000000000000000 > Dumping ftrace buffer: > (ftrace buffer empty) > Kernel Offset: 0x23800000 from 0xffffffff81000000 (relocation range: > 0xffffffff80000000-0xffffffffbfffffff) > Rebooting in 86400 seconds.. > > Here is the reproducer program: https://pastebin.com/TdSTCu5E > > -- > You received this message because you are subscribed to the Google Groups "syzkaller" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller+unsubscribe@googlegroups.com. > For more options, visit https://groups.google.com/d/optout.
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