* [syzbot] WARNING in internal_create_group
@ 2021-07-14 18:57 syzbot
2021-07-20 18:53 ` syzbot
[not found] ` <20210721033703.949-1-hdanton@sina.com>
0 siblings, 2 replies; 8+ messages in thread
From: syzbot @ 2021-07-14 18:57 UTC (permalink / raw)
To: gregkh, linux-kernel, netdev, rafael, syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: 5d52c906f059 Merge git://git.kernel.org/pub/scm/linux/kern..
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=16acf1e2300000
kernel config: https://syzkaller.appspot.com/x/.config?x=51ea6c9df4ed04c4
dashboard link: https://syzkaller.appspot.com/bug?extid=9937dc42271cd87d4b98
Unfortunately, I don't have any reproducer for this issue yet.
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9937dc42271cd87d4b98@syzkaller.appspotmail.com
------------[ cut here ]------------
WARNING: CPU: 1 PID: 9350 at fs/sysfs/group.c:116 internal_create_group+0x911/0xb20 fs/sysfs/group.c:116
Modules linked in:
CPU: 1 PID: 9350 Comm: syz-executor.4 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:internal_create_group+0x911/0xb20 fs/sysfs/group.c:116
Code: 0f 85 e8 f7 ff ff 41 bd ea ff ff ff e9 34 fd ff ff e8 33 bc 82 ff 48 8b 7c 24 08 e8 89 11 ff ff e9 20 fd ff ff e8 1f bc 82 ff <0f> 0b 41 bd ea ff ff ff e9 0e fd ff ff e8 0d bc 82 ff 48 8b 14 24
RSP: 0018:ffffc9000181f2b0 EFLAGS: 00010246
RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc90012931000
RDX: 0000000000040000 RSI: ffffffff81f2c5f1 RDI: 0000000000000003
RBP: ffff8880706b9d08 R08: 0000000000000000 R09: ffff8880706b9d0f
R10: ffffffff81f2bd9e R11: 0000000000000000 R12: 0000000000000000
R13: ffff88809a948070 R14: 0000000000000000 R15: ffff88809a94807c
FS: 00007feaac597700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000006f6c CR3: 000000009d5fa000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
blk_register_queue+0xda/0x570 block/blk-sysfs.c:871
__device_add_disk+0x7b5/0xd10 block/genhd.c:529
add_disk include/linux/genhd.h:217 [inline]
nbd_dev_add+0x712/0x900 drivers/block/nbd.c:1709
nbd_genl_connect+0x551/0x1660 drivers/block/nbd.c:1817
genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:739
genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:800
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340
netlink_sendmsg+0x85b/0xda0 net/netlink/af_netlink.c:1929
sock_sendmsg_nosec net/socket.c:703 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:723
____sys_sendmsg+0x6e8/0x810 net/socket.c:2392
___sys_sendmsg+0xf3/0x170 net/socket.c:2446
__sys_sendmsg+0xe5/0x1b0 net/socket.c:2475
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: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feaac597188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 0000000020000540 RDI: 0000000000000008
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffe11ff566f R14: 00007feaac597300 R15: 0000000000022000
---
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.
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [syzbot] WARNING in internal_create_group 2021-07-14 18:57 [syzbot] WARNING in internal_create_group syzbot @ 2021-07-20 18:53 ` syzbot [not found] ` <20210721033703.949-1-hdanton@sina.com> 1 sibling, 0 replies; 8+ messages in thread From: syzbot @ 2021-07-20 18:53 UTC (permalink / raw) To: gregkh, linux-kernel, netdev, rafael, syzkaller-bugs syzbot has found a reproducer for the following issue on: HEAD commit: 8cae8cd89f05 seq_file: disallow extremely large seq buffer.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=116f92ec300000 kernel config: https://syzkaller.appspot.com/x/.config?x=7273c75708b55890 dashboard link: https://syzkaller.appspot.com/bug?extid=9937dc42271cd87d4b98 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15fc287c300000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=178cbf6a300000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+9937dc42271cd87d4b98@syzkaller.appspotmail.com RSP: 002b:00007ffd8de69d18 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004004a0 RCX: 000000000043fa49 RDX: 0000000000000000 RSI: 00000000200002c0 RDI: 0000000000000004 RBP: 00000000004034b0 R08: 0000000000000000 R09: 00000000004004a0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000403540 R13: 0000000000000000 R14: 00000000004ad018 R15: 00000000004004a0 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 8435 at fs/sysfs/group.c:116 internal_create_group+0x911/0xb20 fs/sysfs/group.c:116 Modules linked in: CPU: 0 PID: 8435 Comm: syz-executor570 Not tainted 5.14.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:internal_create_group+0x911/0xb20 fs/sysfs/group.c:116 Code: 0f 85 e8 f7 ff ff 41 bd ea ff ff ff e9 34 fd ff ff e8 53 3b 82 ff 48 8b 7c 24 08 e8 89 11 ff ff e9 20 fd ff ff e8 3f 3b 82 ff <0f> 0b 41 bd ea ff ff ff e9 0e fd ff ff e8 2d 3b 82 ff 48 8b 14 24 RSP: 0018:ffffc900010ff2a8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff8880284f0000 RSI: ffffffff81f34d91 RDI: 0000000000000003 RBP: ffff88801fd7b9a8 R08: 0000000000000000 R09: ffff88801fd7b9af R10: ffffffff81f3453e R11: 0000000000000000 R12: 0000000000000000 R13: ffff8881455db770 R14: 0000000000000000 R15: ffff8881455db77c FS: 0000000000990300(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f56bbe93740 CR3: 000000001dd48000 CR4: 0000000000350ef0 Call Trace: blk_register_queue+0xda/0x570 block/blk-sysfs.c:871 __device_add_disk+0x7b5/0xd10 block/genhd.c:529 add_disk include/linux/genhd.h:217 [inline] nbd_dev_add+0x73f/0x940 drivers/block/nbd.c:1733 nbd_genl_connect+0x551/0x1820 drivers/block/nbd.c:1842 genl_family_rcv_msg_doit+0x228/0x320 net/netlink/genetlink.c:739 genl_family_rcv_msg net/netlink/genetlink.c:783 [inline] genl_rcv_msg+0x328/0x580 net/netlink/genetlink.c:800 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504 genl_rcv+0x24/0x40 net/netlink/genetlink.c:811 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x86d/0xdb0 net/netlink/af_netlink.c:1929 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:723 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2392 ___sys_sendmsg+0xf3/0x170 net/socket.c:2446 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2475 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: 0033:0x43fa49 Code: 28 c3 e8 5a 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:00007ffd8de69d18 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004004a0 RCX: 000000000043fa49 RDX: 0000000000000000 RSI: 00000000200002c0 RDI: 0000000000000004 RBP: 00000000004034b0 R08: 0000000000000000 R09: 00000000004004a0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000403540 R13: 0000000000000000 R14: 00000000004ad018 R15: 00000000004004a0 ^ permalink raw reply [flat|nested] 8+ messages in thread
[parent not found: <20210721033703.949-1-hdanton@sina.com>]
* Re: [syzbot] WARNING in internal_create_group [not found] ` <20210721033703.949-1-hdanton@sina.com> @ 2021-07-21 4:30 ` Christoph Hellwig 2021-08-11 21:37 ` Pavel Skripkin 0 siblings, 1 reply; 8+ messages in thread From: Christoph Hellwig @ 2021-07-21 4:30 UTC (permalink / raw) To: Hillf Danton Cc: syzbot, linux-kernel, Christoph Hellwig, syzkaller-bugs, Eric Sandeen, Al Viro, Luis Chamberlain, Greg Kroah-Hartman On Wed, Jul 21, 2021 at 11:37:03AM +0800, Hillf Danton wrote: > On Tue, 20 Jul 2021 11:53:27 -0700 > >syzbot has found a reproducer for the following issue on: > > > >HEAD commit: 8cae8cd89f05 seq_file: disallow extremely large seq buffer.. > >git tree: upstream > >console output: https://syzkaller.appspot.com/x/log.txt?x=116f92ec300000 > >kernel config: https://syzkaller.appspot.com/x/.config?x=7273c75708b55890 > >dashboard link: https://syzkaller.appspot.com/bug?extid=9937dc42271cd87d4b98 > >syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15fc287c300000 > >C reproducer: https://syzkaller.appspot.com/x/repro.c?x=178cbf6a300000 <snip> > >WARNING: CPU: 0 PID: 8435 at fs/sysfs/group.c:116 internal_create_group+0x911/0xb20 fs/sysfs/group.c:116 <snip> > The device_add(ddev) in register_disk() may fail but it proceeds to register > block queue even at the failure ... this falls in the class of known issue > given the comment line. > > * FIXME: error handling > */ > static void __device_add_disk(struct device *parent, struct gendisk *disk, Yes, Luis is working on actually fixing this - but it requires changes to every single block driver. How does a cap on the seq_buf size propagate here, though? ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [syzbot] WARNING in internal_create_group 2021-07-21 4:30 ` Christoph Hellwig @ 2021-08-11 21:37 ` Pavel Skripkin 2021-08-12 6:18 ` Christoph Hellwig 2021-09-16 6:55 ` Joel Stanley 0 siblings, 2 replies; 8+ messages in thread From: Pavel Skripkin @ 2021-08-11 21:37 UTC (permalink / raw) To: Christoph Hellwig, Hillf Danton Cc: syzbot, linux-kernel, syzkaller-bugs, Eric Sandeen, Al Viro, Luis Chamberlain, Greg Kroah-Hartman On 7/21/21 7:30 AM, Christoph Hellwig wrote: > On Wed, Jul 21, 2021 at 11:37:03AM +0800, Hillf Danton wrote: >> On Tue, 20 Jul 2021 11:53:27 -0700 >> >syzbot has found a reproducer for the following issue on: >> > >> >HEAD commit: 8cae8cd89f05 seq_file: disallow extremely large seq buffer.. >> >git tree: upstream >> >console output: https://syzkaller.appspot.com/x/log.txt?x=116f92ec300000 >> >kernel config: https://syzkaller.appspot.com/x/.config?x=7273c75708b55890 >> >dashboard link: https://syzkaller.appspot.com/bug?extid=9937dc42271cd87d4b98 >> >syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15fc287c300000 >> >C reproducer: https://syzkaller.appspot.com/x/repro.c?x=178cbf6a300000 > > <snip> > >> >WARNING: CPU: 0 PID: 8435 at fs/sysfs/group.c:116 internal_create_group+0x911/0xb20 fs/sysfs/group.c:116 > > <snip> > >> The device_add(ddev) in register_disk() may fail but it proceeds to register >> block queue even at the failure ... this falls in the class of known issue >> given the comment line. >> >> * FIXME: error handling >> */ >> static void __device_add_disk(struct device *parent, struct gendisk *disk, > > Yes, Luis is working on actually fixing this - but it requires changes > to every single block driver. How does a cap on the seq_buf size > propagate here, though? > Hi! I've looked into this, and, I think, we can add sanity check for first_minor. If user will pass too big index (syzbot's repro passes 1048576) this value will be shifted to part_shift and then truncated to byte in __device_add_disk() and assigned to dev->devt. User may be confused about why he passed 1048576, but sysfs warns about duplicate creation of /dev/block/43:0 So, these type of errors can be handled before passing wrong values to sysfs API like this: diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index c38317979f74..600e9bab5d43 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1725,7 +1725,17 @@ static int nbd_dev_add(int index) refcount_set(&nbd->refs, 1); INIT_LIST_HEAD(&nbd->list); disk->major = NBD_MAJOR; + + /* Too big first_minor can cause duplicate creation of + * sysfs files/links, since first_minor will be truncated to + * byte in __device_add_disk(). + */ disk->first_minor = index << part_shift; + if (disk->first_minor > 0xff) { + err = -EINVAL; + goto out_free_idr; + } + disk->minors = 1 << part_shift; disk->fops = &nbd_fops; disk->private_data = nbd; What to do you think about it? With regards, Pavel Skripkin ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [syzbot] WARNING in internal_create_group 2021-08-11 21:37 ` Pavel Skripkin @ 2021-08-12 6:18 ` Christoph Hellwig 2021-09-16 6:55 ` Joel Stanley 1 sibling, 0 replies; 8+ messages in thread From: Christoph Hellwig @ 2021-08-12 6:18 UTC (permalink / raw) To: Pavel Skripkin Cc: Christoph Hellwig, Hillf Danton, syzbot, linux-kernel, syzkaller-bugs, Eric Sandeen, Al Viro, Luis Chamberlain, Greg Kroah-Hartman On Thu, Aug 12, 2021 at 12:37:08AM +0300, Pavel Skripkin wrote: > --- a/drivers/block/nbd.c > +++ b/drivers/block/nbd.c > @@ -1725,7 +1725,17 @@ static int nbd_dev_add(int index) > refcount_set(&nbd->refs, 1); > INIT_LIST_HEAD(&nbd->list); > disk->major = NBD_MAJOR; > + > + /* Too big first_minor can cause duplicate creation of > + * sysfs files/links, since first_minor will be truncated to > + * byte in __device_add_disk(). > + */ > disk->first_minor = index << part_shift; > + if (disk->first_minor > 0xff) { > + err = -EINVAL; > + goto out_free_idr; > + } > + > disk->minors = 1 << part_shift; > disk->fops = &nbd_fops; > disk->private_data = nbd; > > > What to do you think about it? This sounds reasonable and looks good to me. ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [syzbot] WARNING in internal_create_group 2021-08-11 21:37 ` Pavel Skripkin 2021-08-12 6:18 ` Christoph Hellwig @ 2021-09-16 6:55 ` Joel Stanley 2021-09-16 8:05 ` Greg Kroah-Hartman 2021-09-16 10:56 ` Pavel Skripkin 1 sibling, 2 replies; 8+ messages in thread From: Joel Stanley @ 2021-09-16 6:55 UTC (permalink / raw) To: Pavel Skripkin, Sasha Levin Cc: Christoph Hellwig, Hillf Danton, syzbot, Linux Kernel Mailing List, syzkaller-bugs, Eric Sandeen, Al Viro, Luis Chamberlain, Greg Kroah-Hartman On Wed, 11 Aug 2021 at 21:39, Pavel Skripkin <paskripkin@gmail.com> wrote: > > On 7/21/21 7:30 AM, Christoph Hellwig wrote: > > On Wed, Jul 21, 2021 at 11:37:03AM +0800, Hillf Danton wrote: > >> On Tue, 20 Jul 2021 11:53:27 -0700 > >> >syzbot has found a reproducer for the following issue on: > >> > > >> >HEAD commit: 8cae8cd89f05 seq_file: disallow extremely large seq buffer.. > >> >git tree: upstream > >> >console output: https://syzkaller.appspot.com/x/log.txt?x=116f92ec300000 > >> >kernel config: https://syzkaller.appspot.com/x/.config?x=7273c75708b55890 > >> >dashboard link: https://syzkaller.appspot.com/bug?extid=9937dc42271cd87d4b98 > >> >syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15fc287c300000 > >> >C reproducer: https://syzkaller.appspot.com/x/repro.c?x=178cbf6a300000 > > > > <snip> > > > >> >WARNING: CPU: 0 PID: 8435 at fs/sysfs/group.c:116 internal_create_group+0x911/0xb20 fs/sysfs/group.c:116 > > > > <snip> > > > >> The device_add(ddev) in register_disk() may fail but it proceeds to register > >> block queue even at the failure ... this falls in the class of known issue > >> given the comment line. > >> > >> * FIXME: error handling > >> */ > >> static void __device_add_disk(struct device *parent, struct gendisk *disk, > > > > Yes, Luis is working on actually fixing this - but it requires changes > > to every single block driver. How does a cap on the seq_buf size > > propagate here, though? > > > > Hi! > > I've looked into this, and, I think, we can add sanity check for > first_minor. If user will pass too big index (syzbot's repro passes > 1048576) this value will be shifted to part_shift and then truncated to > byte in __device_add_disk() and assigned to dev->devt. User may be > confused about why he passed 1048576, but sysfs warns about duplicate > creation of /dev/block/43:0 > > So, these type of errors can be handled before passing wrong values to > sysfs API like this: > > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c > index c38317979f74..600e9bab5d43 100644 > --- a/drivers/block/nbd.c > +++ b/drivers/block/nbd.c > @@ -1725,7 +1725,17 @@ static int nbd_dev_add(int index) > refcount_set(&nbd->refs, 1); > INIT_LIST_HEAD(&nbd->list); > disk->major = NBD_MAJOR; > + > + /* Too big first_minor can cause duplicate creation of > + * sysfs files/links, since first_minor will be truncated to > + * byte in __device_add_disk(). > + */ > disk->first_minor = index << part_shift; > + if (disk->first_minor > 0xff) { > + err = -EINVAL; > + goto out_free_idr; > + } > + > disk->minors = 1 << part_shift; > disk->fops = &nbd_fops; > disk->private_data = nbd; > This one got backported to v5.10.65, and causes a warning on boot: [ 7.114976] ------------[ cut here ]------------ [ 7.116811] WARNING: CPU: 0 PID: 1 at block/blk-mq.c:3045 blk_mq_release+0x84/0x114 [ 7.117510] Modules linked in: [ 7.118593] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.65 #196 [ 7.118691] Hardware name: Generic DT based system [ 7.119088] Backtrace: [ 7.119675] [<8093aff0>] (dump_backtrace) from [<8093b294>] (show_stack+0x20/0x24) [ 7.120052] r7:00000009 r6:60000153 r5:00000000 r4:80e75938 [ 7.120223] [<8093b274>] (show_stack) from [<80940938>] (dump_stack+0xc8/0xe4) [ 7.120298] [<80940870>] (dump_stack) from [<80123174>] (__warn+0xe8/0x154) [ 7.120355] r7:00000009 r6:00000be5 r5:804bc594 r4:80b53c80 [ 7.120415] [<8012308c>] (__warn) from [<8093b9b4>] (warn_slowpath_fmt+0x6c/0xe4) [ 7.120465] r7:00000009 r6:00000be5 r5:80b53c80 r4:00000000 [ 7.120537] [<8093b94c>] (warn_slowpath_fmt) from [<804bc594>] (blk_mq_release+0x84/0x114) [ 7.120594] r8:80b53c80 r7:857b7390 r6:00000001 r5:80ea6efd r4:00000000 [ 7.120656] [<804bc510>] (blk_mq_release) from [<804ad65c>] (blk_release_queue+0xb8/0x128) [ 7.120756] r9:00000001 r8:80eee400 r7:00000000 r6:857b7390 r5:00000001 r4:857b73d8 [ 7.120836] [<804ad5a4>] (blk_release_queue) from [<8052f87c>] (kobject_put+0xc8/0x210) [ 7.120891] r7:00000000 r6:00000000 r5:80e751bc r4:857b73d8 [ 7.120948] [<8052f7b4>] (kobject_put) from [<804a9b00>] (blk_put_queue+0x1c/0x20) [ 7.120998] r7:00000000 r6:857b3800 r5:00000000 r4:857b3860 [ 7.121055] [<804a9ae4>] (blk_put_queue) from [<804c2784>] (disk_release+0xb0/0x118) [ 7.121118] [<804c26d4>] (disk_release) from [<805f717c>] (device_release+0x40/0xb4) [ 7.121168] r7:00000000 r6:00000000 r5:00000000 r4:857b3860 [ 7.121224] [<805f713c>] (device_release) from [<8052f87c>] (kobject_put+0xc8/0x210) [ 7.121265] r5:80e81154 r4:857b3860 [ 7.121318] [<8052f7b4>] (kobject_put) from [<804c1c74>] (put_disk+0x24/0x28) [ 7.121368] r7:ffffffea r6:00000008 r5:857b3800 r4:857bca00 [ 7.121440] [<804c1c50>] (put_disk) from [<806286f4>] (nbd_dev_add+0x214/0x27c) [ 7.121670] [<806284e0>] (nbd_dev_add) from [<80d22f80>] (nbd_init+0xec/0x120) [ 7.121740] r10:80ec7000 r9:80c06b34 r8:80d39834 r7:00000000 r6:80e82aa8 r5:00000009 [ 7.121777] r4:00000000 [ 7.121842] [<80d22e94>] (nbd_init) from [<80102364>] (do_one_initcall+0x50/0x274) [ 7.121893] r7:00000000 r6:00000007 r5:8116d180 r4:80d22e94 [ 7.121956] [<80102314>] (do_one_initcall) from [<80d012e8>] (kernel_init_freeable+0x1b8/0x240) [ 7.122005] r7:80d39854 r6:00000007 r5:8116d180 r4:80d5e788 [ 7.122067] [<80d01130>] (kernel_init_freeable) from [<80947bac>] (kernel_init+0x18/0x130) [ 7.122126] r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80947b94 [ 7.122161] r4:00000000 [ 7.122218] [<80947b94>] (kernel_init) from [<80100168>] (ret_from_fork+0x14/0x2c) [ 7.122413] Exception stack(0x810b7fb0 to 0x810b7ff8) [ 7.122936] 7fa0: 00000000 00000000 00000000 00000000 [ 7.123287] 7fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 7.123545] 7fe0: 00000000 00000000 00000000 00000000 00000013 00000000 [ 7.123728] r5:80947b94 r4:00000000 [ 7.124011] ---[ end trace d69e5842dc8c9352 ]--- There's been a bit going on in this driver since v5.10, so I assume it's missing some dependent changes. Cheers, Joel ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [syzbot] WARNING in internal_create_group 2021-09-16 6:55 ` Joel Stanley @ 2021-09-16 8:05 ` Greg Kroah-Hartman 2021-09-16 10:56 ` Pavel Skripkin 1 sibling, 0 replies; 8+ messages in thread From: Greg Kroah-Hartman @ 2021-09-16 8:05 UTC (permalink / raw) To: Joel Stanley Cc: Pavel Skripkin, Sasha Levin, Christoph Hellwig, Hillf Danton, syzbot, Linux Kernel Mailing List, syzkaller-bugs, Eric Sandeen, Al Viro, Luis Chamberlain On Thu, Sep 16, 2021 at 06:55:13AM +0000, Joel Stanley wrote: > On Wed, 11 Aug 2021 at 21:39, Pavel Skripkin <paskripkin@gmail.com> wrote: > > > > On 7/21/21 7:30 AM, Christoph Hellwig wrote: > > > On Wed, Jul 21, 2021 at 11:37:03AM +0800, Hillf Danton wrote: > > >> On Tue, 20 Jul 2021 11:53:27 -0700 > > >> >syzbot has found a reproducer for the following issue on: > > >> > > > >> >HEAD commit: 8cae8cd89f05 seq_file: disallow extremely large seq buffer.. > > >> >git tree: upstream > > >> >console output: https://syzkaller.appspot.com/x/log.txt?x=116f92ec300000 > > >> >kernel config: https://syzkaller.appspot.com/x/.config?x=7273c75708b55890 > > >> >dashboard link: https://syzkaller.appspot.com/bug?extid=9937dc42271cd87d4b98 > > >> >syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15fc287c300000 > > >> >C reproducer: https://syzkaller.appspot.com/x/repro.c?x=178cbf6a300000 > > > > > > <snip> > > > > > >> >WARNING: CPU: 0 PID: 8435 at fs/sysfs/group.c:116 internal_create_group+0x911/0xb20 fs/sysfs/group.c:116 > > > > > > <snip> > > > > > >> The device_add(ddev) in register_disk() may fail but it proceeds to register > > >> block queue even at the failure ... this falls in the class of known issue > > >> given the comment line. > > >> > > >> * FIXME: error handling > > >> */ > > >> static void __device_add_disk(struct device *parent, struct gendisk *disk, > > > > > > Yes, Luis is working on actually fixing this - but it requires changes > > > to every single block driver. How does a cap on the seq_buf size > > > propagate here, though? > > > > > > > Hi! > > > > I've looked into this, and, I think, we can add sanity check for > > first_minor. If user will pass too big index (syzbot's repro passes > > 1048576) this value will be shifted to part_shift and then truncated to > > byte in __device_add_disk() and assigned to dev->devt. User may be > > confused about why he passed 1048576, but sysfs warns about duplicate > > creation of /dev/block/43:0 > > > > So, these type of errors can be handled before passing wrong values to > > sysfs API like this: > > > > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c > > index c38317979f74..600e9bab5d43 100644 > > --- a/drivers/block/nbd.c > > +++ b/drivers/block/nbd.c > > @@ -1725,7 +1725,17 @@ static int nbd_dev_add(int index) > > refcount_set(&nbd->refs, 1); > > INIT_LIST_HEAD(&nbd->list); > > disk->major = NBD_MAJOR; > > + > > + /* Too big first_minor can cause duplicate creation of > > + * sysfs files/links, since first_minor will be truncated to > > + * byte in __device_add_disk(). > > + */ > > disk->first_minor = index << part_shift; > > + if (disk->first_minor > 0xff) { > > + err = -EINVAL; > > + goto out_free_idr; > > + } > > + > > disk->minors = 1 << part_shift; > > disk->fops = &nbd_fops; > > disk->private_data = nbd; > > > > This one got backported to v5.10.65, and causes a warning on boot: > > [ 7.114976] ------------[ cut here ]------------ > [ 7.116811] WARNING: CPU: 0 PID: 1 at block/blk-mq.c:3045 > blk_mq_release+0x84/0x114 > [ 7.117510] Modules linked in: > [ 7.118593] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.65 #196 > [ 7.118691] Hardware name: Generic DT based system > [ 7.119088] Backtrace: > [ 7.119675] [<8093aff0>] (dump_backtrace) from [<8093b294>] > (show_stack+0x20/0x24) > [ 7.120052] r7:00000009 r6:60000153 r5:00000000 r4:80e75938 > [ 7.120223] [<8093b274>] (show_stack) from [<80940938>] > (dump_stack+0xc8/0xe4) > [ 7.120298] [<80940870>] (dump_stack) from [<80123174>] (__warn+0xe8/0x154) > [ 7.120355] r7:00000009 r6:00000be5 r5:804bc594 r4:80b53c80 > [ 7.120415] [<8012308c>] (__warn) from [<8093b9b4>] > (warn_slowpath_fmt+0x6c/0xe4) > [ 7.120465] r7:00000009 r6:00000be5 r5:80b53c80 r4:00000000 > [ 7.120537] [<8093b94c>] (warn_slowpath_fmt) from [<804bc594>] > (blk_mq_release+0x84/0x114) > [ 7.120594] r8:80b53c80 r7:857b7390 r6:00000001 r5:80ea6efd r4:00000000 > [ 7.120656] [<804bc510>] (blk_mq_release) from [<804ad65c>] > (blk_release_queue+0xb8/0x128) > [ 7.120756] r9:00000001 r8:80eee400 r7:00000000 r6:857b7390 > r5:00000001 r4:857b73d8 > [ 7.120836] [<804ad5a4>] (blk_release_queue) from [<8052f87c>] > (kobject_put+0xc8/0x210) > [ 7.120891] r7:00000000 r6:00000000 r5:80e751bc r4:857b73d8 > [ 7.120948] [<8052f7b4>] (kobject_put) from [<804a9b00>] > (blk_put_queue+0x1c/0x20) > [ 7.120998] r7:00000000 r6:857b3800 r5:00000000 r4:857b3860 > [ 7.121055] [<804a9ae4>] (blk_put_queue) from [<804c2784>] > (disk_release+0xb0/0x118) > [ 7.121118] [<804c26d4>] (disk_release) from [<805f717c>] > (device_release+0x40/0xb4) > [ 7.121168] r7:00000000 r6:00000000 r5:00000000 r4:857b3860 > [ 7.121224] [<805f713c>] (device_release) from [<8052f87c>] > (kobject_put+0xc8/0x210) > [ 7.121265] r5:80e81154 r4:857b3860 > [ 7.121318] [<8052f7b4>] (kobject_put) from [<804c1c74>] (put_disk+0x24/0x28) > [ 7.121368] r7:ffffffea r6:00000008 r5:857b3800 r4:857bca00 > [ 7.121440] [<804c1c50>] (put_disk) from [<806286f4>] > (nbd_dev_add+0x214/0x27c) > [ 7.121670] [<806284e0>] (nbd_dev_add) from [<80d22f80>] > (nbd_init+0xec/0x120) > [ 7.121740] r10:80ec7000 r9:80c06b34 r8:80d39834 r7:00000000 > r6:80e82aa8 r5:00000009 > [ 7.121777] r4:00000000 > [ 7.121842] [<80d22e94>] (nbd_init) from [<80102364>] > (do_one_initcall+0x50/0x274) > [ 7.121893] r7:00000000 r6:00000007 r5:8116d180 r4:80d22e94 > [ 7.121956] [<80102314>] (do_one_initcall) from [<80d012e8>] > (kernel_init_freeable+0x1b8/0x240) > [ 7.122005] r7:80d39854 r6:00000007 r5:8116d180 r4:80d5e788 > [ 7.122067] [<80d01130>] (kernel_init_freeable) from [<80947bac>] > (kernel_init+0x18/0x130) > [ 7.122126] r10:00000000 r9:00000000 r8:00000000 r7:00000000 > r6:00000000 r5:80947b94 > [ 7.122161] r4:00000000 > [ 7.122218] [<80947b94>] (kernel_init) from [<80100168>] > (ret_from_fork+0x14/0x2c) > [ 7.122413] Exception stack(0x810b7fb0 to 0x810b7ff8) > [ 7.122936] 7fa0: 00000000 > 00000000 00000000 00000000 > [ 7.123287] 7fc0: 00000000 00000000 00000000 00000000 00000000 > 00000000 00000000 00000000 > [ 7.123545] 7fe0: 00000000 00000000 00000000 00000000 00000013 00000000 > [ 7.123728] r5:80947b94 r4:00000000 > [ 7.124011] ---[ end trace d69e5842dc8c9352 ]--- > > There's been a bit going on in this driver since v5.10, so I assume > it's missing some dependent changes. Ugh, ok, I'll just go revert this for now in here, and in 5.4.y to be safe. thanks, greg k-h ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [syzbot] WARNING in internal_create_group 2021-09-16 6:55 ` Joel Stanley 2021-09-16 8:05 ` Greg Kroah-Hartman @ 2021-09-16 10:56 ` Pavel Skripkin 1 sibling, 0 replies; 8+ messages in thread From: Pavel Skripkin @ 2021-09-16 10:56 UTC (permalink / raw) To: Joel Stanley, Sasha Levin Cc: Christoph Hellwig, Hillf Danton, syzbot, Linux Kernel Mailing List, syzkaller-bugs, Eric Sandeen, Al Viro, Luis Chamberlain, Greg Kroah-Hartman On 9/16/21 09:55, Joel Stanley wrote: > On Wed, 11 Aug 2021 at 21:39, Pavel Skripkin <paskripkin@gmail.com> wrote: >> >> On 7/21/21 7:30 AM, Christoph Hellwig wrote: >> > On Wed, Jul 21, 2021 at 11:37:03AM +0800, Hillf Danton wrote: >> >> On Tue, 20 Jul 2021 11:53:27 -0700 >> >> >syzbot has found a reproducer for the following issue on: >> >> > >> >> >HEAD commit: 8cae8cd89f05 seq_file: disallow extremely large seq buffer.. >> >> >git tree: upstream >> >> >console output: https://syzkaller.appspot.com/x/log.txt?x=116f92ec300000 >> >> >kernel config: https://syzkaller.appspot.com/x/.config?x=7273c75708b55890 >> >> >dashboard link: https://syzkaller.appspot.com/bug?extid=9937dc42271cd87d4b98 >> >> >syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15fc287c300000 >> >> >C reproducer: https://syzkaller.appspot.com/x/repro.c?x=178cbf6a300000 >> > >> > <snip> >> > >> >> >WARNING: CPU: 0 PID: 8435 at fs/sysfs/group.c:116 internal_create_group+0x911/0xb20 fs/sysfs/group.c:116 >> > >> > <snip> >> > >> >> The device_add(ddev) in register_disk() may fail but it proceeds to register >> >> block queue even at the failure ... this falls in the class of known issue >> >> given the comment line. >> >> >> >> * FIXME: error handling >> >> */ >> >> static void __device_add_disk(struct device *parent, struct gendisk *disk, >> > >> > Yes, Luis is working on actually fixing this - but it requires changes >> > to every single block driver. How does a cap on the seq_buf size >> > propagate here, though? >> > >> >> Hi! >> >> I've looked into this, and, I think, we can add sanity check for >> first_minor. If user will pass too big index (syzbot's repro passes >> 1048576) this value will be shifted to part_shift and then truncated to >> byte in __device_add_disk() and assigned to dev->devt. User may be >> confused about why he passed 1048576, but sysfs warns about duplicate >> creation of /dev/block/43:0 >> >> So, these type of errors can be handled before passing wrong values to >> sysfs API like this: >> >> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c >> index c38317979f74..600e9bab5d43 100644 >> --- a/drivers/block/nbd.c >> +++ b/drivers/block/nbd.c >> @@ -1725,7 +1725,17 @@ static int nbd_dev_add(int index) >> refcount_set(&nbd->refs, 1); >> INIT_LIST_HEAD(&nbd->list); >> disk->major = NBD_MAJOR; >> + >> + /* Too big first_minor can cause duplicate creation of >> + * sysfs files/links, since first_minor will be truncated to >> + * byte in __device_add_disk(). >> + */ >> disk->first_minor = index << part_shift; >> + if (disk->first_minor > 0xff) { >> + err = -EINVAL; >> + goto out_free_idr; >> + } >> + >> disk->minors = 1 << part_shift; >> disk->fops = &nbd_fops; >> disk->private_data = nbd; >> > > This one got backported to v5.10.65, and causes a warning on boot: > > [ 7.114976] ------------[ cut here ]------------ > [ 7.116811] WARNING: CPU: 0 PID: 1 at block/blk-mq.c:3045 > blk_mq_release+0x84/0x114 > [ 7.117510] Modules linked in: > [ 7.118593] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.65 #196 > [ 7.118691] Hardware name: Generic DT based system > [ 7.119088] Backtrace: > [ 7.119675] [<8093aff0>] (dump_backtrace) from [<8093b294>] > (show_stack+0x20/0x24) > [ 7.120052] r7:00000009 r6:60000153 r5:00000000 r4:80e75938 > [ 7.120223] [<8093b274>] (show_stack) from [<80940938>] > (dump_stack+0xc8/0xe4) > [ 7.120298] [<80940870>] (dump_stack) from [<80123174>] (__warn+0xe8/0x154) > [ 7.120355] r7:00000009 r6:00000be5 r5:804bc594 r4:80b53c80 > [ 7.120415] [<8012308c>] (__warn) from [<8093b9b4>] > (warn_slowpath_fmt+0x6c/0xe4) > [ 7.120465] r7:00000009 r6:00000be5 r5:80b53c80 r4:00000000 > [ 7.120537] [<8093b94c>] (warn_slowpath_fmt) from [<804bc594>] > (blk_mq_release+0x84/0x114) > [ 7.120594] r8:80b53c80 r7:857b7390 r6:00000001 r5:80ea6efd r4:00000000 > [ 7.120656] [<804bc510>] (blk_mq_release) from [<804ad65c>] > (blk_release_queue+0xb8/0x128) > [ 7.120756] r9:00000001 r8:80eee400 r7:00000000 r6:857b7390 > r5:00000001 r4:857b73d8 > [ 7.120836] [<804ad5a4>] (blk_release_queue) from [<8052f87c>] > (kobject_put+0xc8/0x210) > [ 7.120891] r7:00000000 r6:00000000 r5:80e751bc r4:857b73d8 > [ 7.120948] [<8052f7b4>] (kobject_put) from [<804a9b00>] > (blk_put_queue+0x1c/0x20) > [ 7.120998] r7:00000000 r6:857b3800 r5:00000000 r4:857b3860 > [ 7.121055] [<804a9ae4>] (blk_put_queue) from [<804c2784>] > (disk_release+0xb0/0x118) > [ 7.121118] [<804c26d4>] (disk_release) from [<805f717c>] > (device_release+0x40/0xb4) > [ 7.121168] r7:00000000 r6:00000000 r5:00000000 r4:857b3860 > [ 7.121224] [<805f713c>] (device_release) from [<8052f87c>] > (kobject_put+0xc8/0x210) > [ 7.121265] r5:80e81154 r4:857b3860 > [ 7.121318] [<8052f7b4>] (kobject_put) from [<804c1c74>] (put_disk+0x24/0x28) > [ 7.121368] r7:ffffffea r6:00000008 r5:857b3800 r4:857bca00 > [ 7.121440] [<804c1c50>] (put_disk) from [<806286f4>] > (nbd_dev_add+0x214/0x27c) > [ 7.121670] [<806284e0>] (nbd_dev_add) from [<80d22f80>] > (nbd_init+0xec/0x120) > [ 7.121740] r10:80ec7000 r9:80c06b34 r8:80d39834 r7:00000000 > r6:80e82aa8 r5:00000009 > [ 7.121777] r4:00000000 > [ 7.121842] [<80d22e94>] (nbd_init) from [<80102364>] > (do_one_initcall+0x50/0x274) > [ 7.121893] r7:00000000 r6:00000007 r5:8116d180 r4:80d22e94 > [ 7.121956] [<80102314>] (do_one_initcall) from [<80d012e8>] > (kernel_init_freeable+0x1b8/0x240) > [ 7.122005] r7:80d39854 r6:00000007 r5:8116d180 r4:80d5e788 > [ 7.122067] [<80d01130>] (kernel_init_freeable) from [<80947bac>] > (kernel_init+0x18/0x130) > [ 7.122126] r10:00000000 r9:00000000 r8:00000000 r7:00000000 > r6:00000000 r5:80947b94 > [ 7.122161] r4:00000000 > [ 7.122218] [<80947b94>] (kernel_init) from [<80100168>] > (ret_from_fork+0x14/0x2c) > [ 7.122413] Exception stack(0x810b7fb0 to 0x810b7ff8) > [ 7.122936] 7fa0: 00000000 > 00000000 00000000 00000000 > [ 7.123287] 7fc0: 00000000 00000000 00000000 00000000 00000000 > 00000000 00000000 00000000 > [ 7.123545] 7fe0: 00000000 00000000 00000000 00000000 00000013 00000000 > [ 7.123728] r5:80947b94 r4:00000000 > [ 7.124011] ---[ end trace d69e5842dc8c9352 ]--- > > There's been a bit going on in this driver since v5.10, so I assume > it's missing some dependent changes. > Hi, Joel, Thank you for report! Did reverting my commit remove this warning? I don't get how sanity check could cause this warning, but I might be missing something. With regards, Pavel Skripkin ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2021-09-16 10:56 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
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2021-07-14 18:57 [syzbot] WARNING in internal_create_group syzbot
2021-07-20 18:53 ` syzbot
[not found] ` <20210721033703.949-1-hdanton@sina.com>
2021-07-21 4:30 ` Christoph Hellwig
2021-08-11 21:37 ` Pavel Skripkin
2021-08-12 6:18 ` Christoph Hellwig
2021-09-16 6:55 ` Joel Stanley
2021-09-16 8:05 ` Greg Kroah-Hartman
2021-09-16 10:56 ` Pavel Skripkin
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