| Message ID | 20210310095636.202881-1-eric.dumazet@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | dd4fa1dae9f4847cc1fd78ca468ad69e16e5db3e |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] macvlan: macvlan_count_rx() needs to be aware of preemption | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for net |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | success | CCed 4 of 4 maintainers |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 34 this patch: 34 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 15 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 34 this patch: 34 |
| netdev/header_inline | success | Link |
On Wed, Mar 10, 2021 at 01:56:36AM -0800, Eric Dumazet wrote: > From: Eric Dumazet <edumazet@google.com> > > macvlan_count_rx() can be called from process context, it is thus > necessary to disable preemption before calling u64_stats_update_begin() > > syzbot was able to spot this on 32bit arch: > > WARNING: CPU: 1 PID: 4632 at include/linux/seqlock.h:271 __seqprop_assert include/linux/seqlock.h:271 [inline] > WARNING: CPU: 1 PID: 4632 at include/linux/seqlock.h:271 __seqprop_assert.constprop.0+0xf0/0x11c include/linux/seqlock.h:269 > Modules linked in: > Kernel panic - not syncing: panic_on_warn set ... > CPU: 1 PID: 4632 Comm: kworker/1:3 Not tainted 5.12.0-rc2-syzkaller #0 > Hardware name: ARM-Versatile Express > Workqueue: events macvlan_process_broadcast > Backtrace: > [<82740468>] (dump_backtrace) from [<827406dc>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:252) > r7:00000080 r6:60000093 r5:00000000 r4:8422a3c4 > [<827406c4>] (show_stack) from [<82751b58>] (__dump_stack lib/dump_stack.c:79 [inline]) > [<827406c4>] (show_stack) from [<82751b58>] (dump_stack+0xb8/0xe8 lib/dump_stack.c:120) > [<82751aa0>] (dump_stack) from [<82741270>] (panic+0x130/0x378 kernel/panic.c:231) > r7:830209b4 r6:84069ea4 r5:00000000 r4:844350d0 > [<82741140>] (panic) from [<80244924>] (__warn+0xb0/0x164 kernel/panic.c:605) > r3:8404ec8c r2:00000000 r1:00000000 r0:830209b4 > r7:0000010f > [<80244874>] (__warn) from [<82741520>] (warn_slowpath_fmt+0x68/0xd4 kernel/panic.c:628) > r7:81363f70 r6:0000010f r5:83018e50 r4:00000000 > [<827414bc>] (warn_slowpath_fmt) from [<81363f70>] (__seqprop_assert include/linux/seqlock.h:271 [inline]) > [<827414bc>] (warn_slowpath_fmt) from [<81363f70>] (__seqprop_assert.constprop.0+0xf0/0x11c include/linux/seqlock.h:269) > r8:5a109000 r7:0000000f r6:a568dac0 r5:89802300 r4:00000001 > [<81363e80>] (__seqprop_assert.constprop.0) from [<81364af0>] (u64_stats_update_begin include/linux/u64_stats_sync.h:128 [inline]) > [<81363e80>] (__seqprop_assert.constprop.0) from [<81364af0>] (macvlan_count_rx include/linux/if_macvlan.h:47 [inline]) > [<81363e80>] (__seqprop_assert.constprop.0) from [<81364af0>] (macvlan_broadcast+0x154/0x26c drivers/net/macvlan.c:291) > r5:89802300 r4:8a927740 > [<8136499c>] (macvlan_broadcast) from [<81365020>] (macvlan_process_broadcast+0x258/0x2d0 drivers/net/macvlan.c:317) > r10:81364f78 r9:8a86d000 r8:8a9c7e7c r7:8413aa5c r6:00000000 r5:00000000 > r4:89802840 > [<81364dc8>] (macvlan_process_broadcast) from [<802696a4>] (process_one_work+0x2d4/0x998 kernel/workqueue.c:2275) > r10:00000008 r9:8404ec98 r8:84367a02 r7:ddfe6400 r6:ddfe2d40 r5:898dac80 > r4:8a86d43c > [<802693d0>] (process_one_work) from [<80269dcc>] (worker_thread+0x64/0x54c kernel/workqueue.c:2421) > r10:00000008 r9:8a9c6000 r8:84006d00 r7:ddfe2d78 r6:898dac94 r5:ddfe2d40 > r4:898dac80 > [<80269d68>] (worker_thread) from [<80271f40>] (kthread+0x184/0x1a4 kernel/kthread.c:292) > r10:85247e64 r9:898dac80 r8:80269d68 r7:00000000 r6:8a9c6000 r5:89a2ee40 > r4:8a97bd00 > [<80271dbc>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:158) > Exception stack(0x8a9c7fb0 to 0x8a9c7ff8) > > Fixes: 412ca1550cbe ("macvlan: Move broadcasts into a work queue") > Signed-off-by: Eric Dumazet <edumazet@google.com> > Cc: Herbert Xu <herbert@gondor.apana.org.au> > Reported-by: syzbot <syzkaller@googlegroups.com> > --- > include/linux/if_macvlan.h | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Thanks!
Hello: This patch was applied to netdev/net.git (refs/heads/master): On Wed, 10 Mar 2021 01:56:36 -0800 you wrote: > From: Eric Dumazet <edumazet@google.com> > > macvlan_count_rx() can be called from process context, it is thus > necessary to disable preemption before calling u64_stats_update_begin() > > syzbot was able to spot this on 32bit arch: > > [...] Here is the summary with links: - [net] macvlan: macvlan_count_rx() needs to be aware of preemption https://git.kernel.org/netdev/net/c/dd4fa1dae9f4 You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html
diff --git a/include/linux/if_macvlan.h b/include/linux/if_macvlan.h index 96556c64c95daeff81775132ea93f9758e8d6f27..10c94a3936ca76c782a7e4080046088e83969c1a 100644 --- a/include/linux/if_macvlan.h +++ b/include/linux/if_macvlan.h @@ -43,13 +43,14 @@ static inline void macvlan_count_rx(const struct macvlan_dev *vlan, if (likely(success)) { struct vlan_pcpu_stats *pcpu_stats; - pcpu_stats = this_cpu_ptr(vlan->pcpu_stats); + pcpu_stats = get_cpu_ptr(vlan->pcpu_stats); u64_stats_update_begin(&pcpu_stats->syncp); pcpu_stats->rx_packets++; pcpu_stats->rx_bytes += len; if (multicast) pcpu_stats->rx_multicast++; u64_stats_update_end(&pcpu_stats->syncp); + put_cpu_ptr(vlan->pcpu_stats); } else { this_cpu_inc(vlan->pcpu_stats->rx_errors); }