* [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
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