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authorEric Dumazet <edumazet@google.com>2022-03-12 13:45:05 -0800
committerJakub Kicinski <kuba@kernel.org>2022-03-14 10:15:00 -0700
commitfc93db153b0187a9047f00bfd5cce75108530593 (patch)
tree283709199bba5780732a1b31327fa78fcb73c975 /include/linux/netdevice.h
parentdrivers: net: packetengines: fix typos in comments (diff)
downloadlinux-dev-fc93db153b0187a9047f00bfd5cce75108530593.tar.xz
linux-dev-fc93db153b0187a9047f00bfd5cce75108530593.zip
net: disable preemption in dev_core_stats_XXX_inc() helpers
syzbot was kind enough to remind us that dev->{tx_dropped|rx_dropped} could be increased in process context. BUG: using smp_processor_id() in preemptible [00000000] code: syz-executor413/3593 caller is netdev_core_stats_alloc+0x98/0x110 net/core/dev.c:10298 CPU: 1 PID: 3593 Comm: syz-executor413 Not tainted 5.17.0-rc7-syzkaller-02426-g97aeb877de7f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 check_preemption_disabled+0x16b/0x170 lib/smp_processor_id.c:49 netdev_core_stats_alloc+0x98/0x110 net/core/dev.c:10298 dev_core_stats include/linux/netdevice.h:3855 [inline] dev_core_stats_rx_dropped_inc include/linux/netdevice.h:3866 [inline] tun_get_user+0x3455/0x3ab0 drivers/net/tun.c:1800 tun_chr_write_iter+0xe1/0x200 drivers/net/tun.c:2015 call_write_iter include/linux/fs.h:2074 [inline] new_sync_write+0x431/0x660 fs/read_write.c:503 vfs_write+0x7cd/0xae0 fs/read_write.c:590 ksys_write+0x12d/0x250 fs/read_write.c:643 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: 0033:0x7f2cf4f887e3 Code: 5d 41 5c 41 5d 41 5e e9 9b fd ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 55 c3 0f 1f 40 00 48 83 ec 28 48 89 54 24 18 RSP: 002b:00007ffd50dd5fd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ffd50dd6000 RCX: 00007f2cf4f887e3 RDX: 000000000000002a RSI: 0000000000000000 RDI: 00000000000000c8 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd50dd5ff0 R14: 00007ffd50dd5fe8 R15: 00007ffd50dd5fe4 </TASK> Fixes: 625788b58445 ("net: add per-cpu storage and net->core_stats") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: jeffreyji <jeffreyji@google.com> Cc: Brian Vazquez <brianvv@google.com> Acked-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20220312214505.3294762-1-eric.dumazet@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/linux/netdevice.h')
-rw-r--r--include/linux/netdevice.h6
1 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 0d994710b335..8cbe96ce0a2c 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3858,10 +3858,14 @@ static inline struct net_device_core_stats *dev_core_stats(struct net_device *de
#define DEV_CORE_STATS_INC(FIELD) \
static inline void dev_core_stats_##FIELD##_inc(struct net_device *dev) \
{ \
- struct net_device_core_stats *p = dev_core_stats(dev); \
+ struct net_device_core_stats *p; \
+ \
+ preempt_disable(); \
+ p = dev_core_stats(dev); \
\
if (p) \
local_inc(&p->FIELD); \
+ preempt_enable(); \
}
DEV_CORE_STATS_INC(rx_dropped)
DEV_CORE_STATS_INC(tx_dropped)