From: Florian Westphal fw@strlen.de
commit 28b05b92886871bdd8e6a9df73e3a15845fe8ef4 upstream.
syzbot reports: BUG: using __this_cpu_read() in preemptible code: caller is dev_recursion_level include/linux/netdevice.h:3052 [inline] __this_cpu_preempt_check+0x246/0x270 lib/smp_processor_id.c:47 dev_recursion_level include/linux/netdevice.h:3052 [inline] ip6_skb_dst_mtu include/net/ip6_route.h:245 [inline]
I erronously downgraded a this_cpu_read to __this_cpu_read when moving dev_recursion_level() around.
Reported-by: syzbot+51471b4aae195285a4a3@syzkaller.appspotmail.com Fixes: 97cdcf37b57e ("net: place xmit recursion in softnet data") Signed-off-by: Florian Westphal fw@strlen.de Reviewed-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/linux/netdevice.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 51132debb494..d1e709e6d278 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3132,7 +3132,7 @@ DECLARE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
static inline int dev_recursion_level(void) { - return __this_cpu_read(softnet_data.xmit.recursion); + return this_cpu_read(softnet_data.xmit.recursion); }
#define XMIT_RECURSION_LIMIT 10