Messages in this thread | | | Subject | Re: WARNING in ion_buffer_destroy | From | Laura Abbott <> | Date | Mon, 14 May 2018 13:37:00 -0700 |
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On 05/09/2018 11:59 PM, Dmitry Vyukov wrote: > On Wed, Jan 10, 2018 at 7:14 PM, Laura Abbott <labbott@redhat.com> wrote: >> On 01/09/2018 02:58 PM, syzbot wrote: >>> >>> Hello, >>> >>> syzkaller hit the following crash on >>> 06d41862286aa7bc634a1dd9e6e7e96f925ef30a >>> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master >>> compiler: gcc (GCC) 7.1.1 20170620 >>> .config is attached >>> Raw console output is attached. >>> C reproducer is attached >>> syzkaller reproducer is attached. See https://goo.gl/kgGztJ >>> for information about syzkaller reproducers >>> >>> >>> IMPORTANT: if you fix the bug, please add the following tag to the commit: >>> Reported-by: syzbot+cd8bcd40cb049efa2770@syzkaller.appspotmail.com >>> It will help syzbot understand when the bug is fixed. See footer for >>> details. >>> If you forward the report, please keep this part and the footer. >>> >>> audit: type=1400 audit(1515538424.230:7): avc: denied { map } for >>> pid=3499 comm="syzkaller239906" path="/root/syzkaller239906633" dev="sda1" >>> ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 >>> tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 >>> WARNING: CPU: 0 PID: 1467 at drivers/staging/android/ion/ion.c:122 >>> ion_buffer_destroy+0xd4/0x190 drivers/staging/android/ion/ion.c:122 >>> Kernel panic - not syncing: panic_on_warn set ... >>> >>> CPU: 0 PID: 1467 Comm: ion_system_heap Not tainted >>> 4.15.0-rc7-next-20180109+ #92 >>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS >>> Google 01/01/2011 >>> Call Trace: >>> __dump_stack lib/dump_stack.c:17 [inline] >>> dump_stack+0x194/0x257 lib/dump_stack.c:53 >>> panic+0x1e4/0x41c kernel/panic.c:183 >>> __warn+0x1dc/0x200 kernel/panic.c:547 >>> report_bug+0x211/0x2d0 lib/bug.c:184 >>> fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178 >>> fixup_bug arch/x86/kernel/traps.c:247 [inline] >>> do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 >>> do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 >>> invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:1079 >>> RIP: 0010:ion_buffer_destroy+0xd4/0x190 >>> drivers/staging/android/ion/ion.c:122 >>> RSP: 0018:ffff8801d3a9fd28 EFLAGS: 00010293 >>> RAX: ffff8801d39ee700 RBX: ffff8801c00e57c0 RCX: ffffffff8415d2a4 >>> RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8801d5ada5b8 >>> RBP: ffff8801d3a9fd50 R08: 0000000000000000 R09: 1ffff1003a753f8a >>> R10: ffff8801d3a9fc18 R11: 0000000000000000 R12: ffffffff86e4c980 >>> R13: ffff8801d5ada580 R14: ffff8801c00e57e0 R15: 0000000000000001 >>> ion_heap_deferred_free+0x290/0x650 >>> drivers/staging/android/ion/ion_heap.c:236 >>> kthread+0x33c/0x400 kernel/kthread.c:238 >>> ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524 >>> Dumping ftrace buffer: >>> (ftrace buffer empty) >>> Kernel Offset: disabled >>> Rebooting in 86400 seconds.. >> >> >> This is catching that a buffer was freed with an existing kernel >> map still present. The problem is this can easily be triggered from >> userspace by calling DMA_BUF_SYNC_START without calling >> DMA_BUF_SYNC_END. It's clearly not appropriate for userspace to >> be able to trigger a warning so I'll see about switching this to >> a pr_warn_once. > > Hi Laura, > > Any updates on this? >
I thought I had sent a fix for this but I guess not. I'll see about getting one out.
Thanks, Laura
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