On Wed, Jan 10, 2018 at 7:14 PM, Laura Abbott <labbott@xxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxxxxxxxx >> 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? _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
