| Message ID | 1444665355-28448-1-git-send-email-razor@blackwall.org |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
Mon, Oct 12, 2015 at 05:55:55PM CEST, razor@blackwall.org wrote: >From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> > >commit c62987bbd8a1 ("bridge: push bridge setting ageing_time down to >switchdev") introduced a timer race condition because the gc_timer can >get rearmed after it's supposedly stopped and flushed in br_dev_delete() >leading to a use of freed memory. So take rtnl to sync with bridge >destruction when setting ageing_timer. >Here's the trace reproduced with these two commands running in parallel: >while :; do echo 10000 > /sys/class/net/br0/bridge/ageing_timer; done; >while :; do brctl addbr br0; ip l set br0 up; ip l set br0 down; >brctl delbr br0; done; > >[ 300.000029] BUG: unable to handle kernel paging request at >ffffffff811c59d3 >[ 300.000263] IP: [<ffffffff810f168e>] __internal_add_timer+0x2e/0xd0 >[ 300.000422] PGD 1a0f067 PUD 1a10063 PMD 10001e1 >[ 300.000639] Oops: 0003 [#1] SMP >[ 300.000793] Modules linked in: bridge stp llc nfsd auth_rpcgss >oid_registry nfs_acl nfs lockd grace fscache sunrpc crct10dif_pclmul >crc32_pclmul crc32c_intel ghash_clmulni_intel ppdev aesni_intel >aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd >snd_hda_codec_generic qxl drm_kms_helper psmouse pcspkr ttm >snd_hda_intel 9pnet_virtio evdev serio_raw joydev snd_hda_codec 9pnet >virtio_balloon drm snd_hwdep virtio_console snd_hda_core pvpanic snd_pcm >i2c_piix4 snd_timer acpi_cpufreq parport_pc snd parport soundcore button >processor i2c_core ipv6 autofs4 hid_generic usbhid hid ext4 crc16 >mbcache jbd2 sg sr_mod cdrom ata_generic virtio_blk virtio_net e1000 >ehci_pci uhci_hcd ehci_hcd usbcore usb_common floppy ata_piix libata >virtio_pci virtio_ring virtio scsi_mod >[ 300.004008] CPU: 1 PID: 1169 Comm: bash Not tainted 4.3.0-rc3+ #46 >[ 300.004008] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 >[ 300.004008] task: ffff880035be2200 ti: ffff88003795c000 task.ti: >ffff88003795c000 >[ 300.004008] RIP: 0010:[<ffffffff810f168e>] [<ffffffff810f168e>] >__internal_add_timer+0x2e/0xd0 >[ 300.004008] RSP: 0018:ffff88003fd03e78 EFLAGS: 00010046 >[ 300.004008] RAX: ffff88003fd0ef60 RBX: 840fc78949c08548 RCX: >00000001ffffffff >[ 300.004008] RDX: 0000000000000000 RSI: ffffffff811c59d3 RDI: >ffff88003fd0df00 >[ 300.004008] RBP: ffff88003fd03e78 R08: 00000000ffffffff R09: >0000000000000000 >[ 300.004008] R10: 0000000000000000 R11: 0000000000000000 R12: >ffff88003fd0df00 >[ 300.004008] R13: 0000000000000000 R14: 0000000000000001 R15: >ffffffff816032e0 >[ 300.004008] FS: 00007fcbdd609700(0000) GS:ffff88003fd00000(0000) >knlGS:0000000000000000 >[ 300.004008] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >[ 300.004008] CR2: ffffffff811c59d3 CR3: 0000000037879000 CR4: >00000000000406e0 >[ 300.004008] Stack: >[ 300.004008] ffff88003fd03ea8 ffffffff810f1775 ffff88003c8cb958 >ffff88003fd0df00 >[ 300.004008] 0000000000000000 0000000000000001 ffff88003fd03f18 >ffffffff810f28c4 >[ 300.004008] ffff88003fd0eb68 ffff88003fd0e968 ffff88003fd0e768 >ffff88003fd0df68 >[ 300.004008] Call Trace: >[ 300.004008] <IRQ> >[ 300.004008] [<ffffffff810f1775>] cascade+0x45/0x70 >[ 300.004008] [<ffffffff810f28c4>] run_timer_softirq+0x2f4/0x340 >[ 300.004008] [<ffffffff8107e380>] __do_softirq+0xd0/0x440 >[ 300.004008] [<ffffffff8107e8a3>] irq_exit+0xb3/0xc0 >[ 300.004008] [<ffffffff815c2032>] smp_apic_timer_interrupt+0x42/0x50 >[ 300.004008] [<ffffffff815bfe37>] apic_timer_interrupt+0x87/0x90 >[ 300.004008] <EOI> >[ 300.004008] [<ffffffff811fb80c>] ? create_object+0x13c/0x2e0 >[ 300.004008] [<ffffffff8109b23e>] ? __kernel_text_address+0x4e/0x70 >[ 300.004008] [<ffffffff8109b23e>] ? __kernel_text_address+0x4e/0x70 >[ 300.004008] [<ffffffff8101e17f>] print_context_stack+0x7f/0xf0 >[ 300.004008] [<ffffffff8101d55b>] dump_trace+0x11b/0x300 >[ 300.004008] [<ffffffff8102970b>] save_stack_trace+0x2b/0x50 >[ 300.004008] [<ffffffff811fb80c>] create_object+0x13c/0x2e0 >[ 300.004008] [<ffffffff815b2e8e>] kmemleak_alloc+0x4e/0xb0 >[ 300.004008] [<ffffffff811e475d>] kmem_cache_alloc_trace+0x18d/0x2f0 >[ 300.004008] [<ffffffff8128b139>] kernfs_fop_open+0xc9/0x380 >[ 300.004008] [<ffffffff8120214f>] do_dentry_open+0x1ff/0x2f0 >[ 300.004008] [<ffffffff8128b070>] ? kernfs_fop_release+0x70/0x70 >[ 300.004008] [<ffffffff812034f9>] vfs_open+0x59/0x60 >[ 300.004008] [<ffffffff812130de>] path_openat+0x1ce/0x1260 >[ 300.004008] [<ffffffff812154ae>] do_filp_open+0x7e/0xe0 >[ 300.004008] [<ffffffff812251ff>] ? __alloc_fd+0xaf/0x180 >[ 300.004008] [<ffffffff8120387b>] do_sys_open+0x12b/0x210 >[ 300.004008] [<ffffffff8120397e>] SyS_open+0x1e/0x20 >[ 300.004008] [<ffffffff815bf0b6>] entry_SYSCALL_64_fastpath+0x16/0x7a >[ 300.004008] Code: 66 90 48 8b 46 10 48 8b 4f 40 55 48 89 c2 48 89 e5 >48 29 ca 48 81 fa ff 00 00 00 77 20 0f b6 c0 48 8d 44 c7 68 48 8b 10 48 >85 d2 <48> 89 16 74 04 48 89 72 08 48 89 30 48 89 46 08 5d c3 48 81 fa >[ 300.004008] RIP [<ffffffff810f168e>] __internal_add_timer+0x2e/0xd0 >[ 300.004008] RSP <ffff88003fd03e78> >[ 300.004008] CR2: ffffffff811c59d3 > >Fixes: c62987bbd8a1 ("bridge: push bridge setting ageing_time down to switchdev") >Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Oct 12, 2015 at 8:55 AM, Nikolay Aleksandrov <razor@blackwall.org> wrote: > From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> > > commit c62987bbd8a1 ("bridge: push bridge setting ageing_time down to > switchdev") introduced a timer race condition because the gc_timer can > get rearmed after it's supposedly stopped and flushed in br_dev_delete() > leading to a use of freed memory. So take rtnl to sync with bridge > destruction when setting ageing_timer. > Here's the trace reproduced with these two commands running in parallel: > while :; do echo 10000 > /sys/class/net/br0/bridge/ageing_timer; done; > while :; do brctl addbr br0; ip l set br0 up; ip l set br0 down; > brctl delbr br0; done; > > [ 300.000029] BUG: unable to handle kernel paging request at > ffffffff811c59d3 > [ 300.000263] IP: [<ffffffff810f168e>] __internal_add_timer+0x2e/0xd0 > [ 300.000422] PGD 1a0f067 PUD 1a10063 PMD 10001e1 > [ 300.000639] Oops: 0003 [#1] SMP > [ 300.000793] Modules linked in: bridge stp llc nfsd auth_rpcgss > oid_registry nfs_acl nfs lockd grace fscache sunrpc crct10dif_pclmul > crc32_pclmul crc32c_intel ghash_clmulni_intel ppdev aesni_intel > aes_x86_64 glue_helper lrw gf128mul ablk_helper cryptd > snd_hda_codec_generic qxl drm_kms_helper psmouse pcspkr ttm > snd_hda_intel 9pnet_virtio evdev serio_raw joydev snd_hda_codec 9pnet > virtio_balloon drm snd_hwdep virtio_console snd_hda_core pvpanic snd_pcm > i2c_piix4 snd_timer acpi_cpufreq parport_pc snd parport soundcore button > processor i2c_core ipv6 autofs4 hid_generic usbhid hid ext4 crc16 > mbcache jbd2 sg sr_mod cdrom ata_generic virtio_blk virtio_net e1000 > ehci_pci uhci_hcd ehci_hcd usbcore usb_common floppy ata_piix libata > virtio_pci virtio_ring virtio scsi_mod > [ 300.004008] CPU: 1 PID: 1169 Comm: bash Not tainted 4.3.0-rc3+ #46 > [ 300.004008] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 > [ 300.004008] task: ffff880035be2200 ti: ffff88003795c000 task.ti: > ffff88003795c000 > [ 300.004008] RIP: 0010:[<ffffffff810f168e>] [<ffffffff810f168e>] > __internal_add_timer+0x2e/0xd0 > [ 300.004008] RSP: 0018:ffff88003fd03e78 EFLAGS: 00010046 > [ 300.004008] RAX: ffff88003fd0ef60 RBX: 840fc78949c08548 RCX: > 00000001ffffffff > [ 300.004008] RDX: 0000000000000000 RSI: ffffffff811c59d3 RDI: > ffff88003fd0df00 > [ 300.004008] RBP: ffff88003fd03e78 R08: 00000000ffffffff R09: > 0000000000000000 > [ 300.004008] R10: 0000000000000000 R11: 0000000000000000 R12: > ffff88003fd0df00 > [ 300.004008] R13: 0000000000000000 R14: 0000000000000001 R15: > ffffffff816032e0 > [ 300.004008] FS: 00007fcbdd609700(0000) GS:ffff88003fd00000(0000) > knlGS:0000000000000000 > [ 300.004008] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 300.004008] CR2: ffffffff811c59d3 CR3: 0000000037879000 CR4: > 00000000000406e0 > [ 300.004008] Stack: > [ 300.004008] ffff88003fd03ea8 ffffffff810f1775 ffff88003c8cb958 > ffff88003fd0df00 > [ 300.004008] 0000000000000000 0000000000000001 ffff88003fd03f18 > ffffffff810f28c4 > [ 300.004008] ffff88003fd0eb68 ffff88003fd0e968 ffff88003fd0e768 > ffff88003fd0df68 > [ 300.004008] Call Trace: > [ 300.004008] <IRQ> > [ 300.004008] [<ffffffff810f1775>] cascade+0x45/0x70 > [ 300.004008] [<ffffffff810f28c4>] run_timer_softirq+0x2f4/0x340 > [ 300.004008] [<ffffffff8107e380>] __do_softirq+0xd0/0x440 > [ 300.004008] [<ffffffff8107e8a3>] irq_exit+0xb3/0xc0 > [ 300.004008] [<ffffffff815c2032>] smp_apic_timer_interrupt+0x42/0x50 > [ 300.004008] [<ffffffff815bfe37>] apic_timer_interrupt+0x87/0x90 > [ 300.004008] <EOI> > [ 300.004008] [<ffffffff811fb80c>] ? create_object+0x13c/0x2e0 > [ 300.004008] [<ffffffff8109b23e>] ? __kernel_text_address+0x4e/0x70 > [ 300.004008] [<ffffffff8109b23e>] ? __kernel_text_address+0x4e/0x70 > [ 300.004008] [<ffffffff8101e17f>] print_context_stack+0x7f/0xf0 > [ 300.004008] [<ffffffff8101d55b>] dump_trace+0x11b/0x300 > [ 300.004008] [<ffffffff8102970b>] save_stack_trace+0x2b/0x50 > [ 300.004008] [<ffffffff811fb80c>] create_object+0x13c/0x2e0 > [ 300.004008] [<ffffffff815b2e8e>] kmemleak_alloc+0x4e/0xb0 > [ 300.004008] [<ffffffff811e475d>] kmem_cache_alloc_trace+0x18d/0x2f0 > [ 300.004008] [<ffffffff8128b139>] kernfs_fop_open+0xc9/0x380 > [ 300.004008] [<ffffffff8120214f>] do_dentry_open+0x1ff/0x2f0 > [ 300.004008] [<ffffffff8128b070>] ? kernfs_fop_release+0x70/0x70 > [ 300.004008] [<ffffffff812034f9>] vfs_open+0x59/0x60 > [ 300.004008] [<ffffffff812130de>] path_openat+0x1ce/0x1260 > [ 300.004008] [<ffffffff812154ae>] do_filp_open+0x7e/0xe0 > [ 300.004008] [<ffffffff812251ff>] ? __alloc_fd+0xaf/0x180 > [ 300.004008] [<ffffffff8120387b>] do_sys_open+0x12b/0x210 > [ 300.004008] [<ffffffff8120397e>] SyS_open+0x1e/0x20 > [ 300.004008] [<ffffffff815bf0b6>] entry_SYSCALL_64_fastpath+0x16/0x7a > [ 300.004008] Code: 66 90 48 8b 46 10 48 8b 4f 40 55 48 89 c2 48 89 e5 > 48 29 ca 48 81 fa ff 00 00 00 77 20 0f b6 c0 48 8d 44 c7 68 48 8b 10 48 > 85 d2 <48> 89 16 74 04 48 89 72 08 48 89 30 48 89 46 08 5d c3 48 81 fa > [ 300.004008] RIP [<ffffffff810f168e>] __internal_add_timer+0x2e/0xd0 > [ 300.004008] RSP <ffff88003fd03e78> > [ 300.004008] CR2: ffffffff811c59d3 > > Fixes: c62987bbd8a1 ("bridge: push bridge setting ageing_time down to switchdev") > Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> > --- > net/bridge/br_sysfs_br.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c > index 04ef1926ee7e..8365bd53c421 100644 > --- a/net/bridge/br_sysfs_br.c > +++ b/net/bridge/br_sysfs_br.c > @@ -102,7 +102,15 @@ static ssize_t ageing_time_show(struct device *d, > > static int set_ageing_time(struct net_bridge *br, unsigned long val) > { > - return br_set_ageing_time(br, val); > + int ret; > + > + if (!rtnl_trylock()) > + return restart_syscall(); > + > + ret = br_set_ageing_time(br, val); > + rtnl_unlock(); > + > + return ret; > } Looks good, thanks Nikolay. The other option would have been to simply not restart gc_timer in br_set_ageing_time(), but this would make changes to ageing_time "sluggish" in that it might take a while for the fdb cleanup algo to use the new ageing_time value. By kicking the timer when the ageing_time changes, fdb cleanup immediately switches to the new schedule. In any case, Acked-by: Scott Feldman <sfeldma@gmail.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Nikolay Aleksandrov <razor@blackwall.org> Date: Mon, 12 Oct 2015 17:55:55 +0200 > From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> > > commit c62987bbd8a1 ("bridge: push bridge setting ageing_time down to > switchdev") introduced a timer race condition because the gc_timer can > get rearmed after it's supposedly stopped and flushed in br_dev_delete() > leading to a use of freed memory. So take rtnl to sync with bridge > destruction when setting ageing_timer. > Here's the trace reproduced with these two commands running in parallel: > while :; do echo 10000 > /sys/class/net/br0/bridge/ageing_timer; done; > while :; do brctl addbr br0; ip l set br0 up; ip l set br0 down; > brctl delbr br0; done; ... > Fixes: c62987bbd8a1 ("bridge: push bridge setting ageing_time down to switchdev") > Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/bridge/br_sysfs_br.c b/net/bridge/br_sysfs_br.c index 04ef1926ee7e..8365bd53c421 100644 --- a/net/bridge/br_sysfs_br.c +++ b/net/bridge/br_sysfs_br.c @@ -102,7 +102,15 @@ static ssize_t ageing_time_show(struct device *d, static int set_ageing_time(struct net_bridge *br, unsigned long val) { - return br_set_ageing_time(br, val); + int ret; + + if (!rtnl_trylock()) + return restart_syscall(); + + ret = br_set_ageing_time(br, val); + rtnl_unlock(); + + return ret; } static ssize_t ageing_time_store(struct device *d,