* [syzbot] general protection fault in release_udmabuf
@ 2022-08-19 0:09 syzbot
2022-08-25 6:35 ` [PATCH] udmabuf: Set ubuf->sg = NULL if the creation of sg table fails Vivek Kasireddy
0 siblings, 1 reply; 3+ messages in thread
From: syzbot @ 2022-08-19 0:09 UTC (permalink / raw)
To: christian.koenig, dri-devel, kraxel, linaro-mm-sig, linux-kernel,
linux-media, sumit.semwal, syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: 7ebfc85e2cd7 Merge tag 'net-6.0-rc1' of git://git.kernel.o..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1331f447080000
kernel config: https://syzkaller.appspot.com/x/.config?x=924833c12349a8c0
dashboard link: https://syzkaller.appspot.com/bug?extid=c80e9ef5d8bb45894db0
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=1601336b080000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16d3292d080000
Bisection is inconclusive: the issue happens on the oldest tested release.
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16e01a3d080000
final oops: https://syzkaller.appspot.com/x/report.txt?x=15e01a3d080000
console output: https://syzkaller.appspot.com/x/log.txt?x=11e01a3d080000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c80e9ef5d8bb45894db0@syzkaller.appspotmail.com
general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 PID: 3609 Comm: syz-executor487 Not tainted 5.19.0-syzkaller-13930-g7ebfc85e2cd7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
RIP: 0010:dma_unmap_sgtable include/linux/dma-mapping.h:378 [inline]
RIP: 0010:put_sg_table drivers/dma-buf/udmabuf.c:89 [inline]
RIP: 0010:release_udmabuf+0xcb/0x4f0 drivers/dma-buf/udmabuf.c:114
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 2b 04 00 00 48 8d 7d 0c 4c 8b 63 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 e2
RSP: 0018:ffffc900037efd30 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffffffff8cb67800 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff84ad27e0 RDI: 0000000000000000
RBP: fffffffffffffff4 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000008c07c R12: ffff88801fa05000
R13: ffff888073db07e8 R14: ffff888025c25440 R15: 0000000000000000
FS: 0000555555fc4300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc1c0ce06e4 CR3: 00000000715e6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
dma_buf_release+0x157/0x2d0 drivers/dma-buf/dma-buf.c:78
__dentry_kill+0x42b/0x640 fs/dcache.c:612
dentry_kill fs/dcache.c:733 [inline]
dput+0x806/0xdb0 fs/dcache.c:913
__fput+0x39c/0x9d0 fs/file_table.c:333
task_work_run+0xdd/0x1a0 kernel/task_work.c:177
ptrace_notify+0x114/0x140 kernel/signal.c:2353
ptrace_report_syscall include/linux/ptrace.h:420 [inline]
ptrace_report_syscall_exit include/linux/ptrace.h:482 [inline]
syscall_exit_work kernel/entry/common.c:249 [inline]
syscall_exit_to_user_mode_prepare+0x129/0x280 kernel/entry/common.c:276
__syscall_exit_to_user_mode_work kernel/entry/common.c:281 [inline]
syscall_exit_to_user_mode+0x9/0x50 kernel/entry/common.c:294
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc1c0c35b6b
Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44
RSP: 002b:00007ffd78a06090 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007fc1c0c35b6b
RDX: 0000000020000280 RSI: 0000000040086200 RDI: 0000000000000006
RBP: 0000000000000007 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000000c
R13: 0000000000000003 R14: 00007fc1c0cfe4a0 R15: 00007ffd78a06140
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dma_unmap_sgtable include/linux/dma-mapping.h:378 [inline]
RIP: 0010:put_sg_table drivers/dma-buf/udmabuf.c:89 [inline]
RIP: 0010:release_udmabuf+0xcb/0x4f0 drivers/dma-buf/udmabuf.c:114
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 2b 04 00 00 48 8d 7d 0c 4c 8b 63 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 e2
RSP: 0018:ffffc900037efd30 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffffffff8cb67800 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff84ad27e0 RDI: 0000000000000000
RBP: fffffffffffffff4 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000008c07c R12: ffff88801fa05000
R13: ffff888073db07e8 R14: ffff888025c25440 R15: 0000000000000000
FS: 0000555555fc4300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564b46eeb2c8 CR3: 00000000715e6000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 48 89 fa mov %rdi,%rdx
3: 48 c1 ea 03 shr $0x3,%rdx
7: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
b: 0f 85 2b 04 00 00 jne 0x43c
11: 48 8d 7d 0c lea 0xc(%rbp),%rdi
15: 4c 8b 63 30 mov 0x30(%rbx),%r12
19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
20: fc ff df
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx <-- trapping instruction
2e: 48 89 f8 mov %rdi,%rax
31: 83 e0 07 and $0x7,%eax
34: 83 c0 03 add $0x3,%eax
37: 38 d0 cmp %dl,%al
39: 7c 08 jl 0x43
3b: 84 d2 test %dl,%dl
3d: 0f .byte 0xf
3e: 85 e2 test %esp,%edx
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH] udmabuf: Set ubuf->sg = NULL if the creation of sg table fails
2022-08-19 0:09 [syzbot] general protection fault in release_udmabuf syzbot
@ 2022-08-25 6:35 ` Vivek Kasireddy
2022-08-25 10:00 ` Gerd Hoffmann
0 siblings, 1 reply; 3+ messages in thread
From: Vivek Kasireddy @ 2022-08-25 6:35 UTC (permalink / raw)
To: dri-devel; +Cc: syzbot+c80e9ef5d8bb45894db0, Vivek Kasireddy, Gerd Hoffmann
When userspace tries to map the dmabuf and if for some reason
(e.g. OOM) the creation of the sg table fails, ubuf->sg needs to be
set to NULL. Otherwise, when the userspace subsequently closes the
dmabuf fd, we'd try to erroneously free the invalid sg table from
release_udmabuf resulting in the following crash reported by syzbot:
general protection fault, probably for non-canonical address
0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 PID: 3609 Comm: syz-executor487 Not tainted
5.19.0-syzkaller-13930-g7ebfc85e2cd7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 07/22/2022
RIP: 0010:dma_unmap_sgtable include/linux/dma-mapping.h:378 [inline]
RIP: 0010:put_sg_table drivers/dma-buf/udmabuf.c:89 [inline]
RIP: 0010:release_udmabuf+0xcb/0x4f0 drivers/dma-buf/udmabuf.c:114
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 2b 04 00 00 48 8d 7d 0c 4c
8b 63 30 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14
02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 e2
RSP: 0018:ffffc900037efd30 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffffffff8cb67800 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff84ad27e0 RDI: 0000000000000000
RBP: fffffffffffffff4 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000008c07c R12: ffff88801fa05000
R13: ffff888073db07e8 R14: ffff888025c25440 R15: 0000000000000000
FS: 0000555555fc4300(0000) GS:ffff8880b9a00000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc1c0ce06e4 CR3: 00000000715e6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
dma_buf_release+0x157/0x2d0 drivers/dma-buf/dma-buf.c:78
__dentry_kill+0x42b/0x640 fs/dcache.c:612
dentry_kill fs/dcache.c:733 [inline]
dput+0x806/0xdb0 fs/dcache.c:913
__fput+0x39c/0x9d0 fs/file_table.c:333
task_work_run+0xdd/0x1a0 kernel/task_work.c:177
ptrace_notify+0x114/0x140 kernel/signal.c:2353
ptrace_report_syscall include/linux/ptrace.h:420 [inline]
ptrace_report_syscall_exit include/linux/ptrace.h:482 [inline]
syscall_exit_work kernel/entry/common.c:249 [inline]
syscall_exit_to_user_mode_prepare+0x129/0x280 kernel/entry/common.c:276
__syscall_exit_to_user_mode_work kernel/entry/common.c:281 [inline]
syscall_exit_to_user_mode+0x9/0x50 kernel/entry/common.c:294
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc1c0c35b6b
Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24
0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00
f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44
RSP: 002b:00007ffd78a06090 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007fc1c0c35b6b
RDX: 0000000020000280 RSI: 0000000040086200 RDI: 0000000000000006
RBP: 0000000000000007 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000000c
R13: 0000000000000003 R14: 00007fc1c0cfe4a0 R15: 00007ffd78a06140
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dma_unmap_sgtable include/linux/dma-mapping.h:378 [inline]
RIP: 0010:put_sg_table drivers/dma-buf/udmabuf.c:89 [inline]
RIP: 0010:release_udmabuf+0xcb/0x4f0 drivers/dma-buf/udmabuf.c:114
Reported-by: syzbot+c80e9ef5d8bb45894db0@syzkaller.appspotmail.com
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
---
drivers/dma-buf/udmabuf.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index 38e8767ec371..bf11d32205f3 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -124,17 +124,20 @@ static int begin_cpu_udmabuf(struct dma_buf *buf,
{
struct udmabuf *ubuf = buf->priv;
struct device *dev = ubuf->device->this_device;
+ int ret = 0;
if (!ubuf->sg) {
ubuf->sg = get_sg_table(dev, buf, direction);
- if (IS_ERR(ubuf->sg))
- return PTR_ERR(ubuf->sg);
+ if (IS_ERR(ubuf->sg)) {
+ ret = PTR_ERR(ubuf->sg);
+ ubuf->sg = NULL;
+ }
} else {
dma_sync_sg_for_cpu(dev, ubuf->sg->sgl, ubuf->sg->nents,
direction);
}
- return 0;
+ return ret;
}
static int end_cpu_udmabuf(struct dma_buf *buf,
--
2.35.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] udmabuf: Set ubuf->sg = NULL if the creation of sg table fails
2022-08-25 6:35 ` [PATCH] udmabuf: Set ubuf->sg = NULL if the creation of sg table fails Vivek Kasireddy
@ 2022-08-25 10:00 ` Gerd Hoffmann
0 siblings, 0 replies; 3+ messages in thread
From: Gerd Hoffmann @ 2022-08-25 10:00 UTC (permalink / raw)
To: Vivek Kasireddy; +Cc: syzbot+c80e9ef5d8bb45894db0, dri-devel
On Wed, Aug 24, 2022 at 11:35:22PM -0700, Vivek Kasireddy wrote:
> When userspace tries to map the dmabuf and if for some reason
> (e.g. OOM) the creation of the sg table fails, ubuf->sg needs to be
> set to NULL. Otherwise, when the userspace subsequently closes the
> dmabuf fd, we'd try to erroneously free the invalid sg table from
> release_udmabuf resulting in the following crash reported by syzbot:
>
> general protection fault, probably for non-canonical address
> 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
[ ... ]
> Reported-by: syzbot+c80e9ef5d8bb45894db0@syzkaller.appspotmail.com
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Pushed to drm-misc-next.
thanks,
Gerd
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-08-25 10:01 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2022-08-19 0:09 [syzbot] general protection fault in release_udmabuf syzbot
2022-08-25 6:35 ` [PATCH] udmabuf: Set ubuf->sg = NULL if the creation of sg table fails Vivek Kasireddy
2022-08-25 10:00 ` Gerd Hoffmann
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