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authorEric Dumazet <edumazet@google.com>2019-07-10 16:40:11 +0300
committerDavid S. Miller <davem@davemloft.net>2019-07-12 00:43:25 +0300
commitd44e3fa5d7e6e9573c69f6f9f4f7f3200b0c9eee (patch)
tree7702cf93d482fd2be190fc27a4ac6c3d30f6fb9a /net/ipv6/ip6_flowlabel.c
parent8975a3abc3030bc8cdc3c94b988bcf819a14ed41 (diff)
downloadlinux-d44e3fa5d7e6e9573c69f6f9f4f7f3200b0c9eee.tar.xz
ipv6: fix static key imbalance in fl_create()
fl_create() should call static_branch_deferred_inc() only in case of success. Also we should not call fl_free() in error path, as this could cause a static key imbalance. jump label: negative count! WARNING: CPU: 0 PID: 15907 at kernel/jump_label.c:221 static_key_slow_try_dec kernel/jump_label.c:221 [inline] WARNING: CPU: 0 PID: 15907 at kernel/jump_label.c:221 static_key_slow_try_dec+0x1ab/0x1d0 kernel/jump_label.c:206 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 15907 Comm: syz-executor.2 Not tainted 5.2.0-rc6+ #62 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 panic+0x2cb/0x744 kernel/panic.c:219 __warn.cold+0x20/0x4d kernel/panic.c:576 report_bug+0x263/0x2b0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:179 [inline] fixup_bug arch/x86/kernel/traps.c:174 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:986 RIP: 0010:static_key_slow_try_dec kernel/jump_label.c:221 [inline] RIP: 0010:static_key_slow_try_dec+0x1ab/0x1d0 kernel/jump_label.c:206 Code: c0 e8 e9 3e e5 ff 83 fb 01 0f 85 32 ff ff ff e8 5b 3d e5 ff 45 31 ff eb a0 e8 51 3d e5 ff 48 c7 c7 40 99 92 87 e8 13 75 b7 ff <0f> 0b eb 8b 4c 89 e7 e8 a9 c0 1e 00 e9 de fe ff ff e8 bf 6d b7 ff RSP: 0018:ffff88805f9c7450 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 0000000000000000 RDX: 000000000000e3e1 RSI: ffffffff815adb06 RDI: ffffed100bf38e7c RBP: ffff88805f9c74e0 R08: ffff88806acf0700 R09: ffffed1015d060a9 R10: ffffed1015d060a8 R11: ffff8880ae830547 R12: ffffffff89832ce0 R13: ffff88805f9c74b8 R14: 1ffff1100bf38e8b R15: 00000000ffffff01 __static_key_slow_dec_deferred+0x65/0x110 kernel/jump_label.c:272 fl_free+0xa9/0xe0 net/ipv6/ip6_flowlabel.c:121 fl_create+0x6af/0x9f0 net/ipv6/ip6_flowlabel.c:457 ipv6_flowlabel_opt+0x80e/0x2730 net/ipv6/ip6_flowlabel.c:624 do_ipv6_setsockopt.isra.0+0x2119/0x4100 net/ipv6/ipv6_sockglue.c:825 ipv6_setsockopt+0xf6/0x170 net/ipv6/ipv6_sockglue.c:944 tcp_setsockopt net/ipv4/tcp.c:3131 [inline] tcp_setsockopt+0x8f/0xe0 net/ipv4/tcp.c:3125 sock_common_setsockopt+0x94/0xd0 net/core/sock.c:3130 __sys_setsockopt+0x253/0x4b0 net/socket.c:2080 __do_sys_setsockopt net/socket.c:2096 [inline] __se_sys_setsockopt net/socket.c:2093 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:2093 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4597c9 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2670556c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00000000004597c9 RDX: 0000000000000020 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 000000000075bfc8 R08: 000000000000fdf7 R09: 0000000000000000 R10: 0000000020000000 R11: 0000000000000246 R12: 00007f26705576d4 R13: 00000000004cec00 R14: 00000000004dd520 R15: 00000000ffffffff Kernel Offset: disabled Rebooting in 86400 seconds.. Fixes: 59c820b2317f ("ipv6: elide flowlabel check if no exclusive leases exist") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/ip6_flowlabel.c')
-rw-r--r--net/ipv6/ip6_flowlabel.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
index ad284b1fd308..d64b83e85642 100644
--- a/net/ipv6/ip6_flowlabel.c
+++ b/net/ipv6/ip6_flowlabel.c
@@ -435,8 +435,6 @@ fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
}
fl->dst = freq->flr_dst;
atomic_set(&fl->users, 1);
- if (fl_shared_exclusive(fl) || fl->opt)
- static_branch_deferred_inc(&ipv6_flowlabel_exclusive);
switch (fl->share) {
case IPV6_FL_S_EXCL:
case IPV6_FL_S_ANY:
@@ -451,10 +449,15 @@ fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
err = -EINVAL;
goto done;
}
+ if (fl_shared_exclusive(fl) || fl->opt)
+ static_branch_deferred_inc(&ipv6_flowlabel_exclusive);
return fl;
done:
- fl_free(fl);
+ if (fl) {
+ kfree(fl->opt);
+ kfree(fl);
+ }
*err_p = err;
return NULL;
}