* [syzbot] general protection fault in udmabuf_create
@ 2021-08-10 13:47 syzbot
2021-08-10 14:10 ` Pavel Skripkin
0 siblings, 1 reply; 3+ messages in thread
From: syzbot @ 2021-08-10 13:47 UTC (permalink / raw)
To: christian.koenig, dongwon.kim, dri-devel, kraxel, linaro-mm-sig,
linux-kernel, linux-media, sumit.semwal, syzkaller-bugs,
vivek.kasireddy
Hello,
syzbot found the following issue on:
HEAD commit: 7999516e20bd Add linux-next specific files for 20210806
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=10f15f8e300000
kernel config: https://syzkaller.appspot.com/x/.config?x=2f518e910b029c31
dashboard link: https://syzkaller.appspot.com/bug?extid=e9cd3122a37c5d6c51e8
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1181099a300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11b6fce9300000
The issue was bisected to:
commit 16c243e99d335e1ef3059871897119affc98b493
Author: Vivek Kasireddy <vivek.kasireddy@intel.com>
Date: Wed Jun 9 18:29:15 2021 +0000
udmabuf: Add support for mapping hugepages (v4)
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12f73dc9300000
final oops: https://syzkaller.appspot.com/x/report.txt?x=11f73dc9300000
console output: https://syzkaller.appspot.com/x/log.txt?x=16f73dc9300000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e9cd3122a37c5d6c51e8@syzkaller.appspotmail.com
Fixes: 16c243e99d33 ("udmabuf: Add support for mapping hugepages (v4)")
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 PID: 6603 Comm: syz-executor127 Not tainted 5.14.0-rc4-next-20210806-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:_compound_head include/linux/page-flags.h:187 [inline]
RIP: 0010:get_page include/linux/mm.h:1203 [inline]
RIP: 0010:udmabuf_create+0x664/0x16f0 drivers/dma-buf/udmabuf.c:236
Code: 03 48 89 84 24 90 00 00 00 e9 38 01 00 00 e8 23 7a f7 fc 4d 89 f4 49 c1 e4 06 4c 03 24 24 49 8d 7c 24 08 48 89 f8 48 c1 e8 03 <42> 80 3c 38 00 0f 85 d3 0d 00 00 4d 8b 6c 24 08 31 ff 4c 89 eb 83
RSP: 0018:ffffc90002d7fc70 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888023f69c80 RSI: ffffffff847e4f3d RDI: 0000000000000008
RBP: 0000000000000000 R08: fffffffffffff000 R09: 0000000000000000
R10: ffffffff847e50f5 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS: 0000000000935300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000020c CR3: 0000000018d16000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
udmabuf_ioctl_create drivers/dma-buf/udmabuf.c:305 [inline]
udmabuf_ioctl+0x152/0x2c0 drivers/dma-buf/udmabuf.c:336
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x43eed9
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:00007fff10c6b558 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000400488 RCX: 000000000043eed9
RDX: 0000000020000180 RSI: 0000000040187542 RDI: 0000000000000003
RBP: 0000000000402ec0 R08: 0000000000400488 R09: 0000000000400488
R10: 0000000000400488 R11: 0000000000000246 R12: 0000000000402f50
R13: 0000000000000000 R14: 00000000004ac018 R15: 0000000000400488
Modules linked in:
---[ end trace e38355abd6102561 ]---
RIP: 0010:_compound_head include/linux/page-flags.h:187 [inline]
RIP: 0010:get_page include/linux/mm.h:1203 [inline]
RIP: 0010:udmabuf_create+0x664/0x16f0 drivers/dma-buf/udmabuf.c:236
Code: 03 48 89 84 24 90 00 00 00 e9 38 01 00 00 e8 23 7a f7 fc 4d 89 f4 49 c1 e4 06 4c 03 24 24 49 8d 7c 24 08 48 89 f8 48 c1 e8 03 <42> 80 3c 38 00 0f 85 d3 0d 00 00 4d 8b 6c 24 08 31 ff 4c 89 eb 83
RSP: 0018:ffffc90002d7fc70 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888023f69c80 RSI: ffffffff847e4f3d RDI: 0000000000000008
RBP: 0000000000000000 R08: fffffffffffff000 R09: 0000000000000000
R10: ffffffff847e50f5 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS: 0000000000935300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff86ca0778 CR3: 0000000018d16000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
---
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
* Re: [syzbot] general protection fault in udmabuf_create
2021-08-10 13:47 [syzbot] general protection fault in udmabuf_create syzbot
@ 2021-08-10 14:10 ` Pavel Skripkin
2021-08-10 15:01 ` Dan Carpenter
0 siblings, 1 reply; 3+ messages in thread
From: Pavel Skripkin @ 2021-08-10 14:10 UTC (permalink / raw)
To: syzbot, christian.koenig, dongwon.kim, dri-devel, kraxel,
linaro-mm-sig, linux-kernel, linux-media, sumit.semwal,
syzkaller-bugs, vivek.kasireddy
On 8/10/21 4:47 PM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 7999516e20bd Add linux-next specific files for 20210806
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=10f15f8e300000
> kernel config: https://syzkaller.appspot.com/x/.config?x=2f518e910b029c31
> dashboard link: https://syzkaller.appspot.com/bug?extid=e9cd3122a37c5d6c51e8
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1181099a300000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11b6fce9300000
>
> The issue was bisected to:
>
> commit 16c243e99d335e1ef3059871897119affc98b493
> Author: Vivek Kasireddy <vivek.kasireddy@intel.com>
> Date: Wed Jun 9 18:29:15 2021 +0000
>
> udmabuf: Add support for mapping hugepages (v4)
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12f73dc9300000
> final oops: https://syzkaller.appspot.com/x/report.txt?x=11f73dc9300000
> console output: https://syzkaller.appspot.com/x/log.txt?x=16f73dc9300000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+e9cd3122a37c5d6c51e8@syzkaller.appspotmail.com
> Fixes: 16c243e99d33 ("udmabuf: Add support for mapping hugepages (v4)")
>
> general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
> KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
> CPU: 0 PID: 6603 Comm: syz-executor127 Not tainted 5.14.0-rc4-next-20210806-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> RIP: 0010:_compound_head include/linux/page-flags.h:187 [inline]
> RIP: 0010:get_page include/linux/mm.h:1203 [inline]
> RIP: 0010:udmabuf_create+0x664/0x16f0 drivers/dma-buf/udmabuf.c:236
> Code: 03 48 89 84 24 90 00 00 00 e9 38 01 00 00 e8 23 7a f7 fc 4d 89 f4 49 c1 e4 06 4c 03 24 24 49 8d 7c 24 08 48 89 f8 48 c1 e8 03 <42> 80 3c 38 00 0f 85 d3 0d 00 00 4d 8b 6c 24 08 31 ff 4c 89 eb 83
> RSP: 0018:ffffc90002d7fc70 EFLAGS: 00010202
> RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
> RDX: ffff888023f69c80 RSI: ffffffff847e4f3d RDI: 0000000000000008
> RBP: 0000000000000000 R08: fffffffffffff000 R09: 0000000000000000
> R10: ffffffff847e50f5 R11: 0000000000000000 R12: 0000000000000000
> R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
> FS: 0000000000935300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000000002000020c CR3: 0000000018d16000 CR4: 00000000001506f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> udmabuf_ioctl_create drivers/dma-buf/udmabuf.c:305 [inline]
The problem is wrong error handling:
hpage = find_get_page_flags(mapping, pgoff, FGP_ACCESSED);
if (IS_ERR(hpage)) {
ret = PTR_ERR(hpage);
goto err;
}
find_get_page_flags() return NULL on failure, so this patch should work:
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index 8df761a10251..c57a609db75b 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -227,8 +227,8 @@ static long udmabuf_create(struct miscdevice *device,
if (!hpage) {
hpage = find_get_page_flags(mapping, pgoff,
FGP_ACCESSED);
- if (IS_ERR(hpage)) {
- ret = PTR_ERR(hpage);
+ if (!hpage) {
+ ret = -EINVAL;
goto err;
}
}
I am not sure about ret value in case of failure, so I am looking for
any reviews :)
> udmabuf_ioctl+0x152/0x2c0 drivers/dma-buf/udmabuf.c:336
> vfs_ioctl fs/ioctl.c:51 [inline]
> __do_sys_ioctl fs/ioctl.c:874 [inline]
> __se_sys_ioctl fs/ioctl.c:860 [inline]
> __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
> do_syscall_x64 arch/x86/entry/common.c:50 [inline]
> do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
> entry_SYSCALL_64_after_hwframe+0x44/0xae
With regards,
Pavel Skripkin
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [syzbot] general protection fault in udmabuf_create
2021-08-10 14:10 ` Pavel Skripkin
@ 2021-08-10 15:01 ` Dan Carpenter
0 siblings, 0 replies; 3+ messages in thread
From: Dan Carpenter @ 2021-08-10 15:01 UTC (permalink / raw)
To: Pavel Skripkin
Cc: syzbot, christian.koenig, dongwon.kim, dri-devel, kraxel,
linaro-mm-sig, linux-kernel, linux-media, sumit.semwal,
syzkaller-bugs, vivek.kasireddy
On Tue, Aug 10, 2021 at 05:10:56PM +0300, Pavel Skripkin wrote:
> On 8/10/21 4:47 PM, syzbot wrote:
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit: 7999516e20bd Add linux-next specific files for 20210806
> > git tree: linux-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=10f15f8e300000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=2f518e910b029c31
> > dashboard link: https://syzkaller.appspot.com/bug?extid=e9cd3122a37c5d6c51e8
> > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1181099a300000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11b6fce9300000
> >
> > The issue was bisected to:
> >
> > commit 16c243e99d335e1ef3059871897119affc98b493
> > Author: Vivek Kasireddy <vivek.kasireddy@intel.com>
> > Date: Wed Jun 9 18:29:15 2021 +0000
> >
> > udmabuf: Add support for mapping hugepages (v4)
> >
> > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12f73dc9300000
> > final oops: https://syzkaller.appspot.com/x/report.txt?x=11f73dc9300000
> > console output: https://syzkaller.appspot.com/x/log.txt?x=16f73dc9300000
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+e9cd3122a37c5d6c51e8@syzkaller.appspotmail.com
> > Fixes: 16c243e99d33 ("udmabuf: Add support for mapping hugepages (v4)")
> >
> > general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
> > KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
> > CPU: 0 PID: 6603 Comm: syz-executor127 Not tainted 5.14.0-rc4-next-20210806-syzkaller #0
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > RIP: 0010:_compound_head include/linux/page-flags.h:187 [inline]
> > RIP: 0010:get_page include/linux/mm.h:1203 [inline]
> > RIP: 0010:udmabuf_create+0x664/0x16f0 drivers/dma-buf/udmabuf.c:236
> > Code: 03 48 89 84 24 90 00 00 00 e9 38 01 00 00 e8 23 7a f7 fc 4d 89 f4 49 c1 e4 06 4c 03 24 24 49 8d 7c 24 08 48 89 f8 48 c1 e8 03 <42> 80 3c 38 00 0f 85 d3 0d 00 00 4d 8b 6c 24 08 31 ff 4c 89 eb 83
> > RSP: 0018:ffffc90002d7fc70 EFLAGS: 00010202
> > RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000
> > RDX: ffff888023f69c80 RSI: ffffffff847e4f3d RDI: 0000000000000008
> > RBP: 0000000000000000 R08: fffffffffffff000 R09: 0000000000000000
> > R10: ffffffff847e50f5 R11: 0000000000000000 R12: 0000000000000000
> > R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
> > FS: 0000000000935300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
> > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > CR2: 000000002000020c CR3: 0000000018d16000 CR4: 00000000001506f0
> > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > Call Trace:
> > udmabuf_ioctl_create drivers/dma-buf/udmabuf.c:305 [inline]
>
> The problem is wrong error handling:
>
> hpage = find_get_page_flags(mapping, pgoff, FGP_ACCESSED);
> if (IS_ERR(hpage)) {
> ret = PTR_ERR(hpage);
> goto err;
> }
>
> find_get_page_flags() return NULL on failure, so this patch should work:
>
> diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
> index 8df761a10251..c57a609db75b 100644
> --- a/drivers/dma-buf/udmabuf.c
> +++ b/drivers/dma-buf/udmabuf.c
> @@ -227,8 +227,8 @@ static long udmabuf_create(struct miscdevice *device,
> if (!hpage) {
> hpage = find_get_page_flags(mapping, pgoff,
> FGP_ACCESSED);
> - if (IS_ERR(hpage)) {
> - ret = PTR_ERR(hpage);
> + if (!hpage) {
> + ret = -EINVAL;
> goto err;
> }
> }
>
> I am not sure about ret value in case of failure, so I am looking for any
> reviews :)
You're right. Smatch is sort of supposed to warn about this but
pagecache_get_page() is too complicated.
regards,
dan carpenter
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-08-10 15:02 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2021-08-10 13:47 [syzbot] general protection fault in udmabuf_create syzbot
2021-08-10 14:10 ` Pavel Skripkin
2021-08-10 15:01 ` Dan Carpenter
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