Hello,
syzbot found the following crash on:
HEAD commit: 419593da Add linux-next specific files for 20191129 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=12bfd882e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=7c04b0959e75c206 dashboard link: https://syzkaller.appspot.com/bug?extid=be6ccf3081ce8afd1b56 compiler: gcc (GCC) 9.0.0 20181231 (experimental)
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+be6ccf3081ce8afd1b56@syzkaller.appspotmail.com
BUG: unable to handle page fault for address: fffff52002e00000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 21ffee067 P4D 21ffee067 PUD aa11c067 PMD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 3644 Comm: ion_system_heap Not tainted 5.4.0-next-20191129-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:memory_is_nonzero mm/kasan/generic.c:121 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:135 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:166 [inline] RIP: 0010:check_memory_region_inline mm/kasan/generic.c:182 [inline] RIP: 0010:check_memory_region+0x9c/0x1a0 mm/kasan/generic.c:192 Code: c9 4d 0f 49 c1 49 c1 f8 03 45 85 c0 0f 84 10 01 00 00 41 83 e8 01 4e 8d 44 c0 08 eb 0d 48 83 c0 08 4c 39 c0 0f 84 a7 00 00 00 <48> 83 38 00 74 ed 4c 8d 40 08 eb 09 48 83 c0 01 49 39 c0 74 53 80 RSP: 0018:ffffc9000c9f7ab8 EFLAGS: 00010212 RAX: fffff52002e00000 RBX: fffff52002e01600 RCX: ffffffff85d5c229 RDX: 0000000000000001 RSI: 000000000000b000 RDI: ffffc90017000000 RBP: ffffc9000c9f7ad0 R08: fffff52002e01600 R09: 0000000000001600 R10: fffff52002e015ff R11: ffffc9001700afff R12: fffff52002e00000 R13: 000000000000b000 R14: 0000000000000000 R15: ffffc9000c9f7d08 FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffff52002e00000 CR3: 00000000778bd000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: memset+0x24/0x40 mm/kasan/common.c:107 memset include/linux/string.h:410 [inline] ion_heap_clear_pages+0x49/0x70 drivers/staging/android/ion/ion_heap.c:106 ion_heap_sglist_zero+0x245/0x270 drivers/staging/android/ion/ion_heap.c:130 ion_heap_buffer_zero+0xf5/0x150 drivers/staging/android/ion/ion_heap.c:145 ion_system_heap_free+0x1eb/0x250 drivers/staging/android/ion/ion_system_heap.c:163 ion_buffer_destroy+0x159/0x2d0 drivers/staging/android/ion/ion.c:93 ion_heap_deferred_free+0x29d/0x630 drivers/staging/android/ion/ion_heap.c:239 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Modules linked in: CR2: fffff52002e00000 ---[ end trace ee5c63907f1d6f00 ]--- RIP: 0010:memory_is_nonzero mm/kasan/generic.c:121 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:135 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:166 [inline] RIP: 0010:check_memory_region_inline mm/kasan/generic.c:182 [inline] RIP: 0010:check_memory_region+0x9c/0x1a0 mm/kasan/generic.c:192 Code: c9 4d 0f 49 c1 49 c1 f8 03 45 85 c0 0f 84 10 01 00 00 41 83 e8 01 4e 8d 44 c0 08 eb 0d 48 83 c0 08 4c 39 c0 0f 84 a7 00 00 00 <48> 83 38 00 74 ed 4c 8d 40 08 eb 09 48 83 c0 01 49 39 c0 74 53 80 RSP: 0018:ffffc9000c9f7ab8 EFLAGS: 00010212 RAX: fffff52002e00000 RBX: fffff52002e01600 RCX: ffffffff85d5c229 RDX: 0000000000000001 RSI: 000000000000b000 RDI: ffffc90017000000 RBP: ffffc9000c9f7ad0 R08: fffff52002e01600 R09: 0000000000001600 R10: fffff52002e015ff R11: ffffc9001700afff R12: fffff52002e00000 R13: 000000000000b000 R14: 0000000000000000 R15: ffffc9000c9f7d08 FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffff52002e00000 CR3: 00000000778bd000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
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