From: syzbot <syzbot+2c56b725ec547fa9cb29@syzkaller.appspotmail.com>
To: christian.koenig@amd.com, dri-devel@lists.freedesktop.org,
gurchetansingh@chromium.org, kraxel@redhat.com,
linaro-mm-sig-owner@lists.linaro.org,
linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org,
linux-media@vger.kernel.org, sumit.semwal@linaro.org,
syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] general protection fault in sg_alloc_append_table_from_pages
Date: Sun, 19 Dec 2021 09:27:19 -0800 [thread overview]
Message-ID: <0000000000008ed93005d38315f5@google.com> (raw)
In-Reply-To: <000000000000b0a1a605ce3ec5ad@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: 3f667b5d4053 Merge tag 'tty-5.16-rc6' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=174324a3b00000
kernel config: https://syzkaller.appspot.com/x/.config?x=fa556098924b78f0
dashboard link: https://syzkaller.appspot.com/bug?extid=2c56b725ec547fa9cb29
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14df5c71b00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11d67495b00000
The issue was bisected to:
commit 284562e1f34874e267d4f499362c3816f8f6bc3f
Author: Gurchetan Singh <gurchetansingh@chromium.org>
Date: Tue Dec 3 01:36:27 2019 +0000
udmabuf: implement begin_cpu_access/end_cpu_access hooks
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12d68447300000
final oops: https://syzkaller.appspot.com/x/report.txt?x=11d68447300000
console output: https://syzkaller.appspot.com/x/log.txt?x=16d68447300000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2c56b725ec547fa9cb29@syzkaller.appspotmail.com
Fixes: 284562e1f348 ("udmabuf: implement begin_cpu_access/end_cpu_access hooks")
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 1 PID: 3595 Comm: syz-executor559 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:sg_alloc_append_table_from_pages+0x821/0xdb0 lib/scatterlist.c:525 lib/scatterlist.c:525
Code: 0c 24 48 8b 4c 24 48 48 39 c8 48 0f 46 c8 89 f0 4c 8d 3c c7 48 89 4c 24 30 48 b9 00 00 00 00 00 fc ff df 4c 89 f8 48 c1 e8 03 <80> 3c 08 00 0f 85 24 05 00 00 4d 8b 3f 4c 89 e0 31 ff 83 e0 03 48
RSP: 0018:ffffc90002d0fc48 EFLAGS: 00010212
RAX: 0000000000000002 RBX: 0000000000000001 RCX: dffffc0000000000
RDX: ffff888021fd5700 RSI: 0000000000000000 RDI: 0000000000000010
RBP: 00000000fffff000 R08: fffffffffffff000 R09: ffff8880189ddb00
R10: ffffffff83d88b30 R11: 0000000000000000 R12: 0000000000000002
R13: ffff8880189ddb00 R14: 0000000000000000 R15: 0000000000000010
FS: 000055555652c300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020005b4c CR3: 00000000176ae000 CR4: 0000000000350ee0
Call Trace:
<TASK>
sg_alloc_table_from_pages_segment+0xc9/0x260 lib/scatterlist.c:573 lib/scatterlist.c:573
sg_alloc_table_from_pages include/linux/scatterlist.h:331 [inline]
sg_alloc_table_from_pages include/linux/scatterlist.h:331 [inline] drivers/dma-buf/udmabuf.c:67
get_sg_table.isra.0+0xbb/0x160 drivers/dma-buf/udmabuf.c:67 drivers/dma-buf/udmabuf.c:67
begin_cpu_udmabuf+0x130/0x1d0 drivers/dma-buf/udmabuf.c:126 drivers/dma-buf/udmabuf.c:126
dma_buf_begin_cpu_access+0xfd/0x1d0 drivers/dma-buf/dma-buf.c:1175 drivers/dma-buf/dma-buf.c:1175
dma_buf_ioctl+0x29a/0x380 drivers/dma-buf/dma-buf.c:374 drivers/dma-buf/dma-buf.c:374
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
vfs_ioctl fs/ioctl.c:51 [inline] fs/ioctl.c:860
__do_sys_ioctl fs/ioctl.c:874 [inline] fs/ioctl.c:860
__se_sys_ioctl fs/ioctl.c:860 [inline] fs/ioctl.c:860
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_x64 arch/x86/entry/common.c:50 [inline] arch/x86/entry/common.c:80
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f57966b60a9
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffea34a0a78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f57966b60a9
RDX: 0000000020000000 RSI: 0000000040086200 RDI: 0000000000000004
RBP: 00007f579667a090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f579667a120
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Modules linked in:
---[ end trace ed55bd5e5ccee2ad ]---
RIP: 0010:sg_alloc_append_table_from_pages+0x821/0xdb0 lib/scatterlist.c:525 lib/scatterlist.c:525
Code: 0c 24 48 8b 4c 24 48 48 39 c8 48 0f 46 c8 89 f0 4c 8d 3c c7 48 89 4c 24 30 48 b9 00 00 00 00 00 fc ff df 4c 89 f8 48 c1 e8 03 <80> 3c 08 00 0f 85 24 05 00 00 4d 8b 3f 4c 89 e0 31 ff 83 e0 03 48
RSP: 0018:ffffc90002d0fc48 EFLAGS: 00010212
RAX: 0000000000000002 RBX: 0000000000000001 RCX: dffffc0000000000
RDX: ffff888021fd5700 RSI: 0000000000000000 RDI: 0000000000000010
RBP: 00000000fffff000 R08: fffffffffffff000 R09: ffff8880189ddb00
R10: ffffffff83d88b30 R11: 0000000000000000 R12: 0000000000000002
R13: ffff8880189ddb00 R14: 0000000000000000 R15: 0000000000000010
FS: 000055555652c300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c8ef357220 CR3: 00000000176ae000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
0: 0c 24 or $0x24,%al
2: 48 8b 4c 24 48 mov 0x48(%rsp),%rcx
7: 48 39 c8 cmp %rcx,%rax
a: 48 0f 46 c8 cmovbe %rax,%rcx
e: 89 f0 mov %esi,%eax
10: 4c 8d 3c c7 lea (%rdi,%rax,8),%r15
14: 48 89 4c 24 30 mov %rcx,0x30(%rsp)
19: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
20: fc ff df
23: 4c 89 f8 mov %r15,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction
2e: 0f 85 24 05 00 00 jne 0x558
34: 4d 8b 3f mov (%r15),%r15
37: 4c 89 e0 mov %r12,%rax
3a: 31 ff xor %edi,%edi
3c: 83 e0 03 and $0x3,%eax
3f: 48 rex.W
----------------
Code disassembly (best guess):
0: 0c 24 or $0x24,%al
2: 48 8b 4c 24 48 mov 0x48(%rsp),%rcx
7: 48 39 c8 cmp %rcx,%rax
a: 48 0f 46 c8 cmovbe %rax,%rcx
e: 89 f0 mov %esi,%eax
10: 4c 8d 3c c7 lea (%rdi,%rax,8),%r15
14: 48 89 4c 24 30 mov %rcx,0x30(%rsp)
19: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
20: fc ff df
23: 4c 89 f8 mov %r15,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction
2e: 0f 85 24 05 00 00 jne 0x558
34: 4d 8b 3f mov (%r15),%r15
37: 4c 89 e0 mov %r12,%rax
3a: 31 ff xor %edi,%edi
3c: 83 e0 03 and $0x3,%eax
3f: 48 rex.W
next prev parent reply other threads:[~2021-12-20 8:58 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-13 16:51 [syzbot] general protection fault in sg_alloc_append_table_from_pages syzbot
2021-12-19 17:27 ` syzbot [this message]
2021-12-30 13:53 ` Pavel Skripkin
2021-12-30 14:04 ` syzbot
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