* [syzbot] net-next boot error: WARNING: refcount bug in fib_create_info
@ 2021-08-03 16:07 syzbot
2021-08-03 16:12 ` Pavel Skripkin
0 siblings, 1 reply; 6+ messages in thread
From: syzbot @ 2021-08-03 16:07 UTC (permalink / raw)
To: davem, dsahern, kuba, linux-kernel, netdev, syzkaller-bugs, yoshfuji
Hello,
syzbot found the following issue on:
HEAD commit: 1187c8c4642d net: phy: mscc: make some arrays static const..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=140e7b3e300000
kernel config: https://syzkaller.appspot.com/x/.config?x=f9bb42efdc6f1d7
dashboard link: https://syzkaller.appspot.com/bug?extid=c5ac86461673ef58847c
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c5ac86461673ef58847c@syzkaller.appspotmail.com
FS-Cache: Netfs 'afs' registered for caching
Btrfs loaded, crc32c=crc32c-intel, assert=on, zoned=yes
Key type big_key registered
Key type encrypted registered
AppArmor: AppArmor sha1 policy hashing enabled
ima: No TPM chip found, activating TPM-bypass!
Loading compiled-in module X.509 certificates
Loaded X.509 cert 'Build time autogenerated kernel key: f850c787ad998c396ae089c083b940ff0a9abb77'
ima: Allocated hash algorithm: sha256
ima: No architecture policies found
evm: Initialising EVM extended attributes:
evm: security.selinux (disabled)
evm: security.SMACK64 (disabled)
evm: security.SMACK64EXEC (disabled)
evm: security.SMACK64TRANSMUTE (disabled)
evm: security.SMACK64MMAP (disabled)
evm: security.apparmor
evm: security.ima
evm: security.capability
evm: HMAC attrs: 0x1
PM: Magic number: 1:990:690
printk: console [netcon0] enabled
netconsole: network logging started
gtp: GTP module loaded (pdp ctx size 104 bytes)
rdma_rxe: loaded
cfg80211: Loading compiled-in X.509 certificates for regulatory database
cfg80211: Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
ALSA device list:
#0: Dummy 1
#1: Loopback 1
#2: Virtual MIDI Card 1
md: Waiting for all devices to be available before autodetect
md: If you don't use raid, use raid=noautodetect
md: Autodetecting RAID arrays.
md: autorun ...
md: ... autorun DONE.
EXT4-fs (sda1): mounted filesystem without journal. Opts: (null). Quota mode: none.
VFS: Mounted root (ext4 filesystem) readonly on device 8:1.
devtmpfs: mounted
Freeing unused kernel image (initmem) memory: 4476K
Write protecting the kernel read-only data: 169984k
Freeing unused kernel image (text/rodata gap) memory: 2012K
Freeing unused kernel image (rodata/data gap) memory: 1516K
Run /sbin/init as init process
systemd[1]: systemd 232 running in system mode. (+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD +IDN)
systemd[1]: Detected virtualization kvm.
systemd[1]: Detected architecture x86-64.
systemd[1]: Set hostname to <syzkaller>.
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 1 PID: 1 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
Modules linked in:
CPU: 1 PID: 1 Comm: systemd Not tainted 5.14.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
Code: 09 31 ff 89 de e8 d7 fa 9e fd 84 db 0f 85 36 ff ff ff e8 8a f4 9e fd 48 c7 c7 c0 81 e3 89 c6 05 70 51 81 09 01 e8 48 f8 13 05 <0f> 0b e9 17 ff ff ff e8 6b f4 9e fd 0f b6 1d 55 51 81 09 31 ff 89
RSP: 0018:ffffc90000c66ab0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88813fe48000 RSI: ffffffff815d7b25 RDI: fffff5200018cd48
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff815d195e R11: 0000000000000000 R12: 0000000000000004
R13: 0000000000000001 R14: 0000000000000000 R15: ffff888027722e00
FS: 00007f8c1c5d0500(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ed0ced4368 CR3: 0000000026bac000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__refcount_add include/linux/refcount.h:199 [inline]
__refcount_inc include/linux/refcount.h:250 [inline]
refcount_inc include/linux/refcount.h:267 [inline]
fib_create_info+0x36af/0x4910 net/ipv4/fib_semantics.c:1554
fib_table_insert+0x1cd/0x1af0 net/ipv4/fib_trie.c:1224
fib_magic+0x455/0x540 net/ipv4/fib_frontend.c:1087
fib_add_ifaddr+0x16c/0x500 net/ipv4/fib_frontend.c:1109
fib_inetaddr_event+0x162/0x2a0 net/ipv4/fib_frontend.c:1420
notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
blocking_notifier_call_chain kernel/notifier.c:337 [inline]
blocking_notifier_call_chain+0x67/0x90 kernel/notifier.c:325
__inet_insert_ifa+0x919/0xc20 net/ipv4/devinet.c:553
inet_insert_ifa net/ipv4/devinet.c:560 [inline]
inetdev_event+0x1243/0x15d0 net/ipv4/devinet.c:1570
notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2123
call_netdevice_notifiers_extack net/core/dev.c:2135 [inline]
call_netdevice_notifiers net/core/dev.c:2149 [inline]
__dev_notify_flags+0x110/0x2b0 net/core/dev.c:8878
dev_change_flags+0x112/0x170 net/core/dev.c:8916
do_setlink+0x913/0x3910 net/core/rtnetlink.c:2710
rtnl_setlink+0x24d/0x3c0 net/core/rtnetlink.c:3003
rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5563
netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2504
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:704 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:724
__sys_sendto+0x21c/0x320 net/socket.c:2030
__do_sys_sendto net/socket.c:2042 [inline]
__se_sys_sendto net/socket.c:2038 [inline]
__x64_sys_sendto+0xdd/0x1b0 net/socket.c:2038
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: 0033:0x7f8c1ae6d693
Code: 79 20 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb cd 66 0f 1f 44 00 00 83 3d 39 bd 20 00 00 75 13 49 89 ca b8 2c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 cb f7 ff ff 48 89 04 24
RSP: 002b:00007fffa5944aa8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000055ed0ceca9a0 RCX: 00007f8c1ae6d693
RDX: 0000000000000020 RSI: 000055ed0ceca2b0 RDI: 0000000000000004
RBP: 000055ed0cecaab0 R08: 00007fffa5944ab0 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffa5944b14
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000001
---
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] 6+ messages in thread
* Re: [syzbot] net-next boot error: WARNING: refcount bug in fib_create_info
2021-08-03 16:07 [syzbot] net-next boot error: WARNING: refcount bug in fib_create_info syzbot
@ 2021-08-03 16:12 ` Pavel Skripkin
2021-08-03 16:31 ` Pavel Skripkin
0 siblings, 1 reply; 6+ messages in thread
From: Pavel Skripkin @ 2021-08-03 16:12 UTC (permalink / raw)
To: syzbot, davem, dsahern, kuba, linux-kernel, netdev,
syzkaller-bugs, yoshfuji
On 8/3/21 7:07 PM, syzbot wrote:
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 1187c8c4642d net: phy: mscc: make some arrays static const..
> git tree: net-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=140e7b3e300000
> kernel config: https://syzkaller.appspot.com/x/.config?x=f9bb42efdc6f1d7
> dashboard link: https://syzkaller.appspot.com/bug?extid=c5ac86461673ef58847c
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+c5ac86461673ef58847c@syzkaller.appspotmail.com
>
> FS-Cache: Netfs 'afs' registered for caching
> Btrfs loaded, crc32c=crc32c-intel, assert=on, zoned=yes
> Key type big_key registered
> Key type encrypted registered
> AppArmor: AppArmor sha1 policy hashing enabled
> ima: No TPM chip found, activating TPM-bypass!
> Loading compiled-in module X.509 certificates
> Loaded X.509 cert 'Build time autogenerated kernel key: f850c787ad998c396ae089c083b940ff0a9abb77'
> ima: Allocated hash algorithm: sha256
> ima: No architecture policies found
> evm: Initialising EVM extended attributes:
> evm: security.selinux (disabled)
> evm: security.SMACK64 (disabled)
> evm: security.SMACK64EXEC (disabled)
> evm: security.SMACK64TRANSMUTE (disabled)
> evm: security.SMACK64MMAP (disabled)
> evm: security.apparmor
> evm: security.ima
> evm: security.capability
> evm: HMAC attrs: 0x1
> PM: Magic number: 1:990:690
> printk: console [netcon0] enabled
> netconsole: network logging started
> gtp: GTP module loaded (pdp ctx size 104 bytes)
> rdma_rxe: loaded
> cfg80211: Loading compiled-in X.509 certificates for regulatory database
> cfg80211: Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
> ALSA device list:
> #0: Dummy 1
> #1: Loopback 1
> #2: Virtual MIDI Card 1
> md: Waiting for all devices to be available before autodetect
> md: If you don't use raid, use raid=noautodetect
> md: Autodetecting RAID arrays.
> md: autorun ...
> md: ... autorun DONE.
> EXT4-fs (sda1): mounted filesystem without journal. Opts: (null). Quota mode: none.
> VFS: Mounted root (ext4 filesystem) readonly on device 8:1.
> devtmpfs: mounted
> Freeing unused kernel image (initmem) memory: 4476K
> Write protecting the kernel read-only data: 169984k
> Freeing unused kernel image (text/rodata gap) memory: 2012K
> Freeing unused kernel image (rodata/data gap) memory: 1516K
> Run /sbin/init as init process
> systemd[1]: systemd 232 running in system mode. (+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD +IDN)
> systemd[1]: Detected virtualization kvm.
> systemd[1]: Detected architecture x86-64.
> systemd[1]: Set hostname to <syzkaller>.
> ------------[ cut here ]------------
> refcount_t: addition on 0; use-after-free.
> WARNING: CPU: 1 PID: 1 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
> Modules linked in:
> CPU: 1 PID: 1 Comm: systemd Not tainted 5.14.0-rc3-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> RIP: 0010:refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
> Code: 09 31 ff 89 de e8 d7 fa 9e fd 84 db 0f 85 36 ff ff ff e8 8a f4 9e fd 48 c7 c7 c0 81 e3 89 c6 05 70 51 81 09 01 e8 48 f8 13 05 <0f> 0b e9 17 ff ff ff e8 6b f4 9e fd 0f b6 1d 55 51 81 09 31 ff 89
> RSP: 0018:ffffc90000c66ab0 EFLAGS: 00010286
> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> RDX: ffff88813fe48000 RSI: ffffffff815d7b25 RDI: fffff5200018cd48
> RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000001
> R10: ffffffff815d195e R11: 0000000000000000 R12: 0000000000000004
> R13: 0000000000000001 R14: 0000000000000000 R15: ffff888027722e00
> FS: 00007f8c1c5d0500(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000055ed0ced4368 CR3: 0000000026bac000 CR4: 00000000001506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> __refcount_add include/linux/refcount.h:199 [inline]
> __refcount_inc include/linux/refcount.h:250 [inline]
> refcount_inc include/linux/refcount.h:267 [inline]
> fib_create_info+0x36af/0x4910 net/ipv4/fib_semantics.c:1554
Missed refcount_set(), I think
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index f29feb7772da..bb9949f6bb70 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1428,6 +1428,7 @@ struct fib_info *fib_create_info(struct fib_config
*cfg,
}
fib_info_cnt++;
+ refcount_set(&fi->fib_treeref, 1);
fi->fib_net = net;
fi->fib_protocol = cfg->fc_protocol;
fi->fib_scope = cfg->fc_scope;
With regards,
Pavel Skripkin
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [syzbot] net-next boot error: WARNING: refcount bug in fib_create_info
2021-08-03 16:12 ` Pavel Skripkin
@ 2021-08-03 16:31 ` Pavel Skripkin
2021-08-03 21:04 ` Jakub Kicinski
0 siblings, 1 reply; 6+ messages in thread
From: Pavel Skripkin @ 2021-08-03 16:31 UTC (permalink / raw)
To: syzbot, davem, dsahern, kuba, linux-kernel, netdev,
syzkaller-bugs, yoshfuji
On 8/3/21 7:12 PM, Pavel Skripkin wrote:
> On 8/3/21 7:07 PM, syzbot wrote:
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 1187c8c4642d net: phy: mscc: make some arrays static const..
>> git tree: net-next
>> console output: https://syzkaller.appspot.com/x/log.txt?x=140e7b3e300000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=f9bb42efdc6f1d7
>> dashboard link: https://syzkaller.appspot.com/bug?extid=c5ac86461673ef58847c
>> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: syzbot+c5ac86461673ef58847c@syzkaller.appspotmail.com
>>
>> FS-Cache: Netfs 'afs' registered for caching
>> Btrfs loaded, crc32c=crc32c-intel, assert=on, zoned=yes
>> Key type big_key registered
>> Key type encrypted registered
>> AppArmor: AppArmor sha1 policy hashing enabled
>> ima: No TPM chip found, activating TPM-bypass!
>> Loading compiled-in module X.509 certificates
>> Loaded X.509 cert 'Build time autogenerated kernel key: f850c787ad998c396ae089c083b940ff0a9abb77'
>> ima: Allocated hash algorithm: sha256
>> ima: No architecture policies found
>> evm: Initialising EVM extended attributes:
>> evm: security.selinux (disabled)
>> evm: security.SMACK64 (disabled)
>> evm: security.SMACK64EXEC (disabled)
>> evm: security.SMACK64TRANSMUTE (disabled)
>> evm: security.SMACK64MMAP (disabled)
>> evm: security.apparmor
>> evm: security.ima
>> evm: security.capability
>> evm: HMAC attrs: 0x1
>> PM: Magic number: 1:990:690
>> printk: console [netcon0] enabled
>> netconsole: network logging started
>> gtp: GTP module loaded (pdp ctx size 104 bytes)
>> rdma_rxe: loaded
>> cfg80211: Loading compiled-in X.509 certificates for regulatory database
>> cfg80211: Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
>> ALSA device list:
>> #0: Dummy 1
>> #1: Loopback 1
>> #2: Virtual MIDI Card 1
>> md: Waiting for all devices to be available before autodetect
>> md: If you don't use raid, use raid=noautodetect
>> md: Autodetecting RAID arrays.
>> md: autorun ...
>> md: ... autorun DONE.
>> EXT4-fs (sda1): mounted filesystem without journal. Opts: (null). Quota mode: none.
>> VFS: Mounted root (ext4 filesystem) readonly on device 8:1.
>> devtmpfs: mounted
>> Freeing unused kernel image (initmem) memory: 4476K
>> Write protecting the kernel read-only data: 169984k
>> Freeing unused kernel image (text/rodata gap) memory: 2012K
>> Freeing unused kernel image (rodata/data gap) memory: 1516K
>> Run /sbin/init as init process
>> systemd[1]: systemd 232 running in system mode. (+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD +IDN)
>> systemd[1]: Detected virtualization kvm.
>> systemd[1]: Detected architecture x86-64.
>> systemd[1]: Set hostname to <syzkaller>.
>> ------------[ cut here ]------------
>> refcount_t: addition on 0; use-after-free.
>> WARNING: CPU: 1 PID: 1 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
>> Modules linked in:
>> CPU: 1 PID: 1 Comm: systemd Not tainted 5.14.0-rc3-syzkaller #0
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
>> RIP: 0010:refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
>> Code: 09 31 ff 89 de e8 d7 fa 9e fd 84 db 0f 85 36 ff ff ff e8 8a f4 9e fd 48 c7 c7 c0 81 e3 89 c6 05 70 51 81 09 01 e8 48 f8 13 05 <0f> 0b e9 17 ff ff ff e8 6b f4 9e fd 0f b6 1d 55 51 81 09 31 ff 89
>> RSP: 0018:ffffc90000c66ab0 EFLAGS: 00010286
>> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
>> RDX: ffff88813fe48000 RSI: ffffffff815d7b25 RDI: fffff5200018cd48
>> RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000001
>> R10: ffffffff815d195e R11: 0000000000000000 R12: 0000000000000004
>> R13: 0000000000000001 R14: 0000000000000000 R15: ffff888027722e00
>> FS: 00007f8c1c5d0500(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 000055ed0ced4368 CR3: 0000000026bac000 CR4: 00000000001506e0
>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>> Call Trace:
>> __refcount_add include/linux/refcount.h:199 [inline]
>> __refcount_inc include/linux/refcount.h:250 [inline]
>> refcount_inc include/linux/refcount.h:267 [inline]
>> fib_create_info+0x36af/0x4910 net/ipv4/fib_semantics.c:1554
>
> Missed refcount_set(), I think
>
> diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
> index f29feb7772da..bb9949f6bb70 100644
> --- a/net/ipv4/fib_semantics.c
> +++ b/net/ipv4/fib_semantics.c
> @@ -1428,6 +1428,7 @@ struct fib_info *fib_create_info(struct fib_config
> *cfg,
> }
>
> fib_info_cnt++;
> + refcount_set(&fi->fib_treeref, 1);
> fi->fib_net = net;
> fi->fib_protocol = cfg->fc_protocol;
> fi->fib_scope = cfg->fc_scope;
>
>
>
>
>
Oops, it's already fixed in -next, so
#syz fix: ipv4: Fix refcount warning for new fib_info
BTW: there is one more bug with refcounts:
link_it:
ofi = fib_find_info(fi);
if (ofi) {
fi->fib_dead = 1;
free_fib_info(fi);
refcount_inc(&ofi->fib_treeref);
^^^^^^^^^^^^^^^^^^^^^^^
/ *fib_treeref is 0 here */
return ofi;
}
refcount_set(&fi->fib_treeref, 1);
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index f29feb7772da..38d1fc4d0be1 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1543,6 +1543,8 @@ struct fib_info *fib_create_info(struct fib_config
*cfg,
}
link_it:
+ refcount_set(&fi->fib_treeref, 1);
+
ofi = fib_find_info(fi);
if (ofi) {
fi->fib_dead = 1;
@@ -1551,7 +1553,6 @@ struct fib_info *fib_create_info(struct fib_config
*cfg,
return ofi;
}
- refcount_set(&fi->fib_treeref, 1);
refcount_set(&fi->fib_clntref, 1);
spin_lock_bh(&fib_info_lock);
hlist_add_head(&fi->fib_hash,
Thoughts?
With regards,
Pavel Skripkin
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [syzbot] net-next boot error: WARNING: refcount bug in fib_create_info
2021-08-03 16:31 ` Pavel Skripkin
@ 2021-08-03 21:04 ` Jakub Kicinski
2021-08-03 22:32 ` David Ahern
2021-08-04 5:05 ` Pavel Skripkin
0 siblings, 2 replies; 6+ messages in thread
From: Jakub Kicinski @ 2021-08-03 21:04 UTC (permalink / raw)
To: Pavel Skripkin
Cc: syzbot, davem, dsahern, linux-kernel, netdev, syzkaller-bugs, yoshfuji
On Tue, 3 Aug 2021 19:31:50 +0300 Pavel Skripkin wrote:
> On 8/3/21 7:12 PM, Pavel Skripkin wrote:
> > On 8/3/21 7:07 PM, syzbot wrote:
> >> Hello,
> >>
> >> syzbot found the following issue on:
> >>
> >> HEAD commit: 1187c8c4642d net: phy: mscc: make some arrays static const..
> >> git tree: net-next
> >> console output: https://syzkaller.appspot.com/x/log.txt?x=140e7b3e300000
> >> kernel config: https://syzkaller.appspot.com/x/.config?x=f9bb42efdc6f1d7
> >> dashboard link: https://syzkaller.appspot.com/bug?extid=c5ac86461673ef58847c
> >> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
> >>
> >> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> >> Reported-by: syzbot+c5ac86461673ef58847c@syzkaller.appspotmail.com
> >>
> >> FS-Cache: Netfs 'afs' registered for caching
> >> Btrfs loaded, crc32c=crc32c-intel, assert=on, zoned=yes
> >> Key type big_key registered
> >> Key type encrypted registered
> >> AppArmor: AppArmor sha1 policy hashing enabled
> >> ima: No TPM chip found, activating TPM-bypass!
> >> Loading compiled-in module X.509 certificates
> >> Loaded X.509 cert 'Build time autogenerated kernel key: f850c787ad998c396ae089c083b940ff0a9abb77'
> >> ima: Allocated hash algorithm: sha256
> >> ima: No architecture policies found
> >> evm: Initialising EVM extended attributes:
> >> evm: security.selinux (disabled)
> >> evm: security.SMACK64 (disabled)
> >> evm: security.SMACK64EXEC (disabled)
> >> evm: security.SMACK64TRANSMUTE (disabled)
> >> evm: security.SMACK64MMAP (disabled)
> >> evm: security.apparmor
> >> evm: security.ima
> >> evm: security.capability
> >> evm: HMAC attrs: 0x1
> >> PM: Magic number: 1:990:690
> >> printk: console [netcon0] enabled
> >> netconsole: network logging started
> >> gtp: GTP module loaded (pdp ctx size 104 bytes)
> >> rdma_rxe: loaded
> >> cfg80211: Loading compiled-in X.509 certificates for regulatory database
> >> cfg80211: Loaded X.509 cert 'sforshee: 00b28ddf47aef9cea7'
> >> ALSA device list:
> >> #0: Dummy 1
> >> #1: Loopback 1
> >> #2: Virtual MIDI Card 1
> >> md: Waiting for all devices to be available before autodetect
> >> md: If you don't use raid, use raid=noautodetect
> >> md: Autodetecting RAID arrays.
> >> md: autorun ...
> >> md: ... autorun DONE.
> >> EXT4-fs (sda1): mounted filesystem without journal. Opts: (null). Quota mode: none.
> >> VFS: Mounted root (ext4 filesystem) readonly on device 8:1.
> >> devtmpfs: mounted
> >> Freeing unused kernel image (initmem) memory: 4476K
> >> Write protecting the kernel read-only data: 169984k
> >> Freeing unused kernel image (text/rodata gap) memory: 2012K
> >> Freeing unused kernel image (rodata/data gap) memory: 1516K
> >> Run /sbin/init as init process
> >> systemd[1]: systemd 232 running in system mode. (+PAM +AUDIT +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD +IDN)
> >> systemd[1]: Detected virtualization kvm.
> >> systemd[1]: Detected architecture x86-64.
> >> systemd[1]: Set hostname to <syzkaller>.
> >> ------------[ cut here ]------------
> >> refcount_t: addition on 0; use-after-free.
> >> WARNING: CPU: 1 PID: 1 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
> >> Modules linked in:
> >> CPU: 1 PID: 1 Comm: systemd Not tainted 5.14.0-rc3-syzkaller #0
> >> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> >> RIP: 0010:refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
> >> Code: 09 31 ff 89 de e8 d7 fa 9e fd 84 db 0f 85 36 ff ff ff e8 8a f4 9e fd 48 c7 c7 c0 81 e3 89 c6 05 70 51 81 09 01 e8 48 f8 13 05 <0f> 0b e9 17 ff ff ff e8 6b f4 9e fd 0f b6 1d 55 51 81 09 31 ff 89
> >> RSP: 0018:ffffc90000c66ab0 EFLAGS: 00010286
> >> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> >> RDX: ffff88813fe48000 RSI: ffffffff815d7b25 RDI: fffff5200018cd48
> >> RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000001
> >> R10: ffffffff815d195e R11: 0000000000000000 R12: 0000000000000004
> >> R13: 0000000000000001 R14: 0000000000000000 R15: ffff888027722e00
> >> FS: 00007f8c1c5d0500(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
> >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> >> CR2: 000055ed0ced4368 CR3: 0000000026bac000 CR4: 00000000001506e0
> >> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> >> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> >> Call Trace:
> >> __refcount_add include/linux/refcount.h:199 [inline]
> >> __refcount_inc include/linux/refcount.h:250 [inline]
> >> refcount_inc include/linux/refcount.h:267 [inline]
> >> fib_create_info+0x36af/0x4910 net/ipv4/fib_semantics.c:1554
> >
> > Missed refcount_set(), I think
> >
> > diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
> > index f29feb7772da..bb9949f6bb70 100644
> > --- a/net/ipv4/fib_semantics.c
> > +++ b/net/ipv4/fib_semantics.c
> > @@ -1428,6 +1428,7 @@ struct fib_info *fib_create_info(struct fib_config
> > *cfg,
> > }
> >
> > fib_info_cnt++;
> > + refcount_set(&fi->fib_treeref, 1);
> > fi->fib_net = net;
> > fi->fib_protocol = cfg->fc_protocol;
> > fi->fib_scope = cfg->fc_scope;
>
> Oops, it's already fixed in -next, so
>
> #syz fix: ipv4: Fix refcount warning for new fib_info
>
>
> BTW: there is one more bug with refcounts:
>
> link_it:
> ofi = fib_find_info(fi);
> if (ofi) {
> fi->fib_dead = 1;
> free_fib_info(fi);
> refcount_inc(&ofi->fib_treeref);
>
> ^^^^^^^^^^^^^^^^^^^^^^^
> / *fib_treeref is 0 here */
Why 0? ofi is an existing object it's already initialized.
> return ofi;
> }
>
> refcount_set(&fi->fib_treeref, 1);
>
>
> diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
> index f29feb7772da..38d1fc4d0be1 100644
> --- a/net/ipv4/fib_semantics.c
> +++ b/net/ipv4/fib_semantics.c
> @@ -1543,6 +1543,8 @@ struct fib_info *fib_create_info(struct fib_config
> *cfg,
> }
>
> link_it:
> + refcount_set(&fi->fib_treeref, 1);
> +
> ofi = fib_find_info(fi);
> if (ofi) {
> fi->fib_dead = 1;
> @@ -1551,7 +1553,6 @@ struct fib_info *fib_create_info(struct fib_config
> *cfg,
> return ofi;
> }
>
> - refcount_set(&fi->fib_treeref, 1);
> refcount_set(&fi->fib_clntref, 1);
> spin_lock_bh(&fib_info_lock);
> hlist_add_head(&fi->fib_hash,
>
>
> Thoughts?
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [syzbot] net-next boot error: WARNING: refcount bug in fib_create_info
2021-08-03 21:04 ` Jakub Kicinski
@ 2021-08-03 22:32 ` David Ahern
2021-08-04 5:05 ` Pavel Skripkin
1 sibling, 0 replies; 6+ messages in thread
From: David Ahern @ 2021-08-03 22:32 UTC (permalink / raw)
To: Jakub Kicinski, Pavel Skripkin
Cc: syzbot, davem, dsahern, linux-kernel, netdev, syzkaller-bugs, yoshfuji
On 8/3/21 3:04 PM, Jakub Kicinski wrote:
>>>
>>> diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
>>> index f29feb7772da..bb9949f6bb70 100644
>>> --- a/net/ipv4/fib_semantics.c
>>> +++ b/net/ipv4/fib_semantics.c
>>> @@ -1428,6 +1428,7 @@ struct fib_info *fib_create_info(struct fib_config
>>> *cfg,
>>> }
>>>
>>> fib_info_cnt++;
>>> + refcount_set(&fi->fib_treeref, 1);
>>> fi->fib_net = net;
>>> fi->fib_protocol = cfg->fc_protocol;
>>> fi->fib_scope = cfg->fc_scope;
>>
>> Oops, it's already fixed in -next, so
>>
>> #syz fix: ipv4: Fix refcount warning for new fib_info
>>
>>
>> BTW: there is one more bug with refcounts:
>>
>> link_it:
>> ofi = fib_find_info(fi);
>> if (ofi) {
>> fi->fib_dead = 1;
>> free_fib_info(fi);
>> refcount_inc(&ofi->fib_treeref);
>>
>> ^^^^^^^^^^^^^^^^^^^^^^^
>> / *fib_treeref is 0 here */
>
> Why 0? ofi is an existing object it's already initialized.
yes, it is an existing object with a non-0 refcount.
>
>> return ofi;
>> }
>>
>> refcount_set(&fi->fib_treeref, 1);
>>
>>
>> diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
>> index f29feb7772da..38d1fc4d0be1 100644
>> --- a/net/ipv4/fib_semantics.c
>> +++ b/net/ipv4/fib_semantics.c
>> @@ -1543,6 +1543,8 @@ struct fib_info *fib_create_info(struct fib_config
>> *cfg,
>> }
>>
>> link_it:
>> + refcount_set(&fi->fib_treeref, 1);
moving the refcount_set here causes all kinds of problems with the
release and error paths in this function.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [syzbot] net-next boot error: WARNING: refcount bug in fib_create_info
2021-08-03 21:04 ` Jakub Kicinski
2021-08-03 22:32 ` David Ahern
@ 2021-08-04 5:05 ` Pavel Skripkin
1 sibling, 0 replies; 6+ messages in thread
From: Pavel Skripkin @ 2021-08-04 5:05 UTC (permalink / raw)
To: Jakub Kicinski
Cc: syzbot, davem, dsahern, linux-kernel, netdev, syzkaller-bugs, yoshfuji
On Tue, 3 Aug 2021 14:04:35 -0700
Jakub Kicinski <kuba@kernel.org> wrote:
> On Tue, 3 Aug 2021 19:31:50 +0300 Pavel Skripkin wrote:
> > On 8/3/21 7:12 PM, Pavel Skripkin wrote:
> > > On 8/3/21 7:07 PM, syzbot wrote:
> > >> Hello,
> > >>
> > >> syzbot found the following issue on:
> > >>
> > >> HEAD commit: 1187c8c4642d net: phy: mscc: make some arrays
> > >> static const.. git tree: net-next
> > >> console output:
> > >> https://syzkaller.appspot.com/x/log.txt?x=140e7b3e300000 kernel
> > >> config:
> > >> https://syzkaller.appspot.com/x/.config?x=f9bb42efdc6f1d7
> > >> dashboard link:
> > >> https://syzkaller.appspot.com/bug?extid=c5ac86461673ef58847c
> > >> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld
> > >> (GNU Binutils for Debian) 2.35.1
> > >>
> > >> IMPORTANT: if you fix the issue, please add the following tag to
> > >> the commit: Reported-by:
> > >> syzbot+c5ac86461673ef58847c@syzkaller.appspotmail.com
> > >>
> > >> FS-Cache: Netfs 'afs' registered for caching
> > >> Btrfs loaded, crc32c=crc32c-intel, assert=on, zoned=yes
> > >> Key type big_key registered
> > >> Key type encrypted registered
> > >> AppArmor: AppArmor sha1 policy hashing enabled
> > >> ima: No TPM chip found, activating TPM-bypass!
> > >> Loading compiled-in module X.509 certificates
> > >> Loaded X.509 cert 'Build time autogenerated kernel key:
> > >> f850c787ad998c396ae089c083b940ff0a9abb77' ima: Allocated hash
> > >> algorithm: sha256 ima: No architecture policies found
> > >> evm: Initialising EVM extended attributes:
> > >> evm: security.selinux (disabled)
> > >> evm: security.SMACK64 (disabled)
> > >> evm: security.SMACK64EXEC (disabled)
> > >> evm: security.SMACK64TRANSMUTE (disabled)
> > >> evm: security.SMACK64MMAP (disabled)
> > >> evm: security.apparmor
> > >> evm: security.ima
> > >> evm: security.capability
> > >> evm: HMAC attrs: 0x1
> > >> PM: Magic number: 1:990:690
> > >> printk: console [netcon0] enabled
> > >> netconsole: network logging started
> > >> gtp: GTP module loaded (pdp ctx size 104 bytes)
> > >> rdma_rxe: loaded
> > >> cfg80211: Loading compiled-in X.509 certificates for regulatory
> > >> database cfg80211: Loaded X.509 cert 'sforshee:
> > >> 00b28ddf47aef9cea7' ALSA device list:
> > >> #0: Dummy 1
> > >> #1: Loopback 1
> > >> #2: Virtual MIDI Card 1
> > >> md: Waiting for all devices to be available before autodetect
> > >> md: If you don't use raid, use raid=noautodetect
> > >> md: Autodetecting RAID arrays.
> > >> md: autorun ...
> > >> md: ... autorun DONE.
> > >> EXT4-fs (sda1): mounted filesystem without journal. Opts:
> > >> (null). Quota mode: none. VFS: Mounted root (ext4 filesystem)
> > >> readonly on device 8:1. devtmpfs: mounted
> > >> Freeing unused kernel image (initmem) memory: 4476K
> > >> Write protecting the kernel read-only data: 169984k
> > >> Freeing unused kernel image (text/rodata gap) memory: 2012K
> > >> Freeing unused kernel image (rodata/data gap) memory: 1516K
> > >> Run /sbin/init as init process
> > >> systemd[1]: systemd 232 running in system mode. (+PAM +AUDIT
> > >> +SELINUX +IMA +APPARMOR +SMACK +SYSVINIT +UTMP +LIBCRYPTSETUP
> > >> +GCRYPT +GNUTLS +ACL +XZ +LZ4 +SECCOMP +BLKID +ELFUTILS +KMOD
> > >> +IDN) systemd[1]: Detected virtualization kvm. systemd[1]:
> > >> Detected architecture x86-64. systemd[1]: Set hostname to
> > >> <syzkaller>. ------------[ cut here ]------------ refcount_t:
> > >> addition on 0; use-after-free. WARNING: CPU: 1 PID: 1 at
> > >> lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0
> > >> lib/refcount.c:25 Modules linked in: CPU: 1 PID: 1 Comm: systemd
> > >> Not tainted 5.14.0-rc3-syzkaller #0 Hardware name: Google Google
> > >> Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > >> RIP: 0010:refcount_warn_saturate+0x169/0x1e0 lib/refcount.c:25
> > >> Code: 09 31 ff 89 de e8 d7 fa 9e fd 84 db 0f 85 36 ff ff ff e8
> > >> 8a f4 9e fd 48 c7 c7 c0 81 e3 89 c6 05 70 51 81 09 01 e8 48 f8
> > >> 13 05 <0f> 0b e9 17 ff ff ff e8 6b f4 9e fd 0f b6 1d 55 51 81 09
> > >> 31 ff 89 RSP: 0018:ffffc90000c66ab0 EFLAGS: 00010286 RAX:
> > >> 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> > >> RDX: ffff88813fe48000 RSI: ffffffff815d7b25 RDI:
> > >> fffff5200018cd48 RBP: 0000000000000002 R08: 0000000000000000
> > >> R09: 0000000000000001 R10: ffffffff815d195e R11:
> > >> 0000000000000000 R12: 0000000000000004 R13: 0000000000000001
> > >> R14: 0000000000000000 R15: ffff888027722e00 FS:
> > >> 00007f8c1c5d0500(0000) GS:ffff8880b9d00000(0000)
> > >> knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0:
> > >> 0000000080050033 CR2: 000055ed0ced4368 CR3: 0000000026bac000
> > >> CR4: 00000000001506e0 DR0: 0000000000000000 DR1:
> > >> 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000
> > >> DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace:
> > >> __refcount_add include/linux/refcount.h:199 [inline]
> > >> __refcount_inc include/linux/refcount.h:250 [inline]
> > >> refcount_inc include/linux/refcount.h:267 [inline]
> > >> fib_create_info+0x36af/0x4910 net/ipv4/fib_semantics.c:1554
> > >
> > > Missed refcount_set(), I think
> > >
> > > diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
> > > index f29feb7772da..bb9949f6bb70 100644
> > > --- a/net/ipv4/fib_semantics.c
> > > +++ b/net/ipv4/fib_semantics.c
> > > @@ -1428,6 +1428,7 @@ struct fib_info *fib_create_info(struct
> > > fib_config *cfg,
> > > }
> > >
> > > fib_info_cnt++;
> > > + refcount_set(&fi->fib_treeref, 1);
> > > fi->fib_net = net;
> > > fi->fib_protocol = cfg->fc_protocol;
> > > fi->fib_scope = cfg->fc_scope;
> >
> > Oops, it's already fixed in -next, so
> >
> > #syz fix: ipv4: Fix refcount warning for new fib_info
> >
> >
> > BTW: there is one more bug with refcounts:
> >
> > link_it:
> > ofi = fib_find_info(fi);
> > if (ofi) {
> > fi->fib_dead = 1;
> > free_fib_info(fi);
> > refcount_inc(&ofi->fib_treeref);
> >
> > ^^^^^^^^^^^^^^^^^^^^^^^
> > / *fib_treeref is 0 here */
>
> Why 0? ofi is an existing object it's already initialized.
>
Yep, I see now, sorry for misinformation :(
With regards,
Pavel Skripkin
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-08-04 5:05 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-03 16:07 [syzbot] net-next boot error: WARNING: refcount bug in fib_create_info syzbot
2021-08-03 16:12 ` Pavel Skripkin
2021-08-03 16:31 ` Pavel Skripkin
2021-08-03 21:04 ` Jakub Kicinski
2021-08-03 22:32 ` David Ahern
2021-08-04 5:05 ` Pavel Skripkin
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).