Thread (21 messages) 21 messages, 2 authors, 2018-02-21
STALE3061d REVIEWED: 1 (1M)
Revisions (202)
  1. v1 [diff vs current]
  2. v1 [diff vs current]
  3. v1 [diff vs current]
  4. v1 [diff vs current]
  5. v1 [diff vs current]
  6. v1 [diff vs current]
  7. v1 [diff vs current]
  8. v1 [diff vs current]
  9. v1 [diff vs current]
  10. v1 [diff vs current]
  11. v1 [diff vs current]
  12. v1 [diff vs current]
  13. v1 [diff vs current]
  14. v1 [diff vs current]
  15. v1 [diff vs current]
  16. v1 [diff vs current]
  17. v1 [diff vs current]
  18. v1 [diff vs current]
  19. v1 [diff vs current]
  20. v1 [diff vs current]
  21. v1 [diff vs current]
  22. v1 [diff vs current]
  23. v1 [diff vs current]
  24. v1 [diff vs current]
  25. v1 [diff vs current]
  26. v1 [diff vs current]
  27. v1 [diff vs current]
  28. v1 [diff vs current]
  29. v1 [diff vs current]
  30. v1 [diff vs current]
  31. v1 [diff vs current]
  32. v1 [diff vs current]
  33. v1 [diff vs current]
  34. v1 [diff vs current]
  35. v1 [diff vs current]
  36. v1 [diff vs current]
  37. v1 [diff vs current]
  38. v1 [diff vs current]
  39. v1 [diff vs current]
  40. v1 [diff vs current]
  41. v1 [diff vs current]
  42. v1 [diff vs current]
  43. v1 [diff vs current]
  44. v1 [diff vs current]
  45. v1 [diff vs current]
  46. v1 [diff vs current]
  47. v1 [diff vs current]
  48. v1 [diff vs current]
  49. v1 current
  50. v1 [diff vs current]
  51. v1 [diff vs current]
  52. v1 [diff vs current]
  53. v1 [diff vs current]
  54. v1 [diff vs current]
  55. v1 [diff vs current]
  56. v1 [diff vs current]
  57. v1 [diff vs current]
  58. v1 [diff vs current]
  59. v1 [diff vs current]
  60. v1 [diff vs current]
  61. v1 [diff vs current]
  62. v1 [diff vs current]
  63. v1 [diff vs current]
  64. v1 [diff vs current]
  65. v1 [diff vs current]
  66. v1 [diff vs current]
  67. v1 [diff vs current]
  68. v1 [diff vs current]
  69. v1 [diff vs current]
  70. v1 [diff vs current]
  71. v1 [diff vs current]
  72. v1 [diff vs current]
  73. v1 [diff vs current]
  74. v1 [diff vs current]
  75. v1 [diff vs current]
  76. v1 [diff vs current]
  77. v1 [diff vs current]
  78. v1 [diff vs current]
  79. v1 [diff vs current]
  80. v1 [diff vs current]
  81. v1 [diff vs current]
  82. v1 [diff vs current]
  83. v1 [diff vs current]
  84. v1 [diff vs current]
  85. v1 [diff vs current]
  86. v1 [diff vs current]
  87. v1 [diff vs current]
  88. v1 [diff vs current]
  89. v1 [diff vs current]
  90. v1 [diff vs current]
  91. v1 [diff vs current]
  92. v1 [diff vs current]
  93. v1 [diff vs current]
  94. v1 [diff vs current]
  95. v1 [diff vs current]
  96. v1 [diff vs current]
  97. v1 [diff vs current]
  98. v1 [diff vs current]
  99. v1 [diff vs current]
  100. v1 [diff vs current]
  101. v1 [diff vs current]
  102. v1 [diff vs current]
  103. v1 [diff vs current]
  104. v1 [diff vs current]
  105. v1 [diff vs current]
  106. v1 [diff vs current]
  107. v1 [diff vs current]
  108. v1 [diff vs current]
  109. v1 [diff vs current]
  110. v1 [diff vs current]
  111. v2 [diff vs current]
  112. v1 [diff vs current]
  113. v1 [diff vs current]
  114. v1 [diff vs current]
  115. v1 [diff vs current]
  116. v1 [diff vs current]
  117. v1 [diff vs current]
  118. v1 [diff vs current]
  119. v1 [diff vs current]
  120. v1 [diff vs current]
  121. v1 [diff vs current]
  122. v1 [diff vs current]
  123. v2 [diff vs current]
  124. v1 [diff vs current]
  125. v1 [diff vs current]
  126. v1 [diff vs current]
  127. v1 [diff vs current]
  128. v1 [diff vs current]
  129. v1 [diff vs current]
  130. v1 [diff vs current]
  131. v1 [diff vs current]
  132. v1 [diff vs current]
  133. v1 [diff vs current]
  134. v1 [diff vs current]
  135. v1 [diff vs current]
  136. v1 [diff vs current]
  137. v1 [diff vs current]
  138. v1 [diff vs current]
  139. v1 [diff vs current]
  140. v1 [diff vs current]
  141. v1 [diff vs current]
  142. v1 [diff vs current]
  143. v1 [diff vs current]
  144. v1 [diff vs current]
  145. v1 [diff vs current]
  146. v1 [diff vs current]
  147. v1 [diff vs current]
  148. v1 [diff vs current]
  149. v1 [diff vs current]
  150. v1 [diff vs current]
  151. v1 [diff vs current]
  152. v1 [diff vs current]
  153. v1 [diff vs current]
  154. v1 [diff vs current]
  155. v1 [diff vs current]
  156. v1 [diff vs current]
  157. v1 [diff vs current]
  158. v1 [diff vs current]
  159. v1 [diff vs current]
  160. v2 [diff vs current]
  161. v1 [diff vs current]
  162. v1 [diff vs current]
  163. v1 [diff vs current]
  164. v2 [diff vs current]
  165. v1 [diff vs current]
  166. v1 [diff vs current]
  167. v1 [diff vs current]
  168. v1 [diff vs current]
  169. v2 [diff vs current]
  170. v1 [diff vs current]
  171. v1 [diff vs current]
  172. v1 [diff vs current]
  173. v1 [diff vs current]
  174. v3 [diff vs current]
  175. v1 [diff vs current]
  176. v1 [diff vs current]
  177. v1 [diff vs current]
  178. v1 [diff vs current]
  179. v1 [diff vs current]
  180. v2 [diff vs current]
  181. v1 [diff vs current]
  182. v1 [diff vs current]
  183. v1 [diff vs current]
  184. v1 [diff vs current]
  185. v1 [diff vs current]
  186. v2 [diff vs current]
  187. v1 [diff vs current]
  188. v1 [diff vs current]
  189. v1 [diff vs current]
  190. v1 [diff vs current]
  191. v1 [diff vs current]
  192. v1 [diff vs current]
  193. v1 [diff vs current]
  194. v2 [diff vs current]
  195. v1 [diff vs current]
  196. v2 [diff vs current]
  197. v1 [diff vs current]
  198. v1 [diff vs current]
  199. v1 [diff vs current]
  200. v1 [diff vs current]
  201. v2 [diff vs current]
  202. v1 [diff vs current]

[PATCH 03/19] netfilter: drop outermost socket lock in getsockopt()

From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2018-02-20 16:39:17
Subsystem: networking [general], networking [ipv4/ipv6], the rest · Maintainers: "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds 

From: Paolo Abeni <pabeni@redhat.com>

The Syzbot reported a possible deadlock in the netfilter area caused by
rtnl lock, xt lock and socket lock being acquired with a different order
on different code paths, leading to the following backtrace:
Reviewed-by: Xin Long <lucien.xin@gmail.com>

======================================================
WARNING: possible circular locking dependency detected
4.15.0+ #301 Not tainted
------------------------------------------------------
syzkaller233489/4179 is trying to acquire lock:
  (rtnl_mutex){+.+.}, at: [<0000000048e996fd>] rtnl_lock+0x17/0x20
net/core/rtnetlink.c:74

but task is already holding lock:
  (&xt[i].mutex){+.+.}, at: [<00000000328553a2>]
xt_find_table_lock+0x3e/0x3e0 net/netfilter/x_tables.c:1041

which lock already depends on the new lock.
===

Since commit 3f34cfae1230 ("netfilter: on sockopt() acquire sock lock
only in the required scope"), we already acquire the socket lock in
the innermost scope, where needed. In such commit I forgot to remove
the outer-most socket lock from the getsockopt() path, this commit
addresses the issues dropping it now.

v1 -> v2: fix bad subj, added relavant 'fixes' tag

Fixes: 22265a5c3c10 ("netfilter: xt_TEE: resolve oif using netdevice notifiers")
Fixes: 202f59afd441 ("netfilter: ipt_CLUSTERIP: do not hold dev")
Fixes: 3f34cfae1230 ("netfilter: on sockopt() acquire sock lock only in the required scope")
Reported-by: syzbot+ddde1c7b7ff7442d7f2d@syzkaller.appspotmail.com
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/ipv4/ip_sockglue.c   |  7 +------
 net/ipv6/ipv6_sockglue.c | 10 ++--------
 2 files changed, 3 insertions(+), 14 deletions(-)

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 008be04ac1cc..9c41a0cef1a5 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -1567,10 +1567,7 @@ int ip_getsockopt(struct sock *sk, int level,
 		if (get_user(len, optlen))
 			return -EFAULT;
 
-		lock_sock(sk);
-		err = nf_getsockopt(sk, PF_INET, optname, optval,
-				&len);
-		release_sock(sk);
+		err = nf_getsockopt(sk, PF_INET, optname, optval, &len);
 		if (err >= 0)
 			err = put_user(len, optlen);
 		return err;
@@ -1602,9 +1599,7 @@ int compat_ip_getsockopt(struct sock *sk, int level, int optname,
 		if (get_user(len, optlen))
 			return -EFAULT;
 
-		lock_sock(sk);
 		err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len);
-		release_sock(sk);
 		if (err >= 0)
 			err = put_user(len, optlen);
 		return err;
diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index d78d41fc4b1a..24535169663d 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -1367,10 +1367,7 @@ int ipv6_getsockopt(struct sock *sk, int level, int optname,
 		if (get_user(len, optlen))
 			return -EFAULT;
 
-		lock_sock(sk);
-		err = nf_getsockopt(sk, PF_INET6, optname, optval,
-				&len);
-		release_sock(sk);
+		err = nf_getsockopt(sk, PF_INET6, optname, optval, &len);
 		if (err >= 0)
 			err = put_user(len, optlen);
 	}
@@ -1409,10 +1406,7 @@ int compat_ipv6_getsockopt(struct sock *sk, int level, int optname,
 		if (get_user(len, optlen))
 			return -EFAULT;
 
-		lock_sock(sk);
-		err = compat_nf_getsockopt(sk, PF_INET6,
-					   optname, optval, &len);
-		release_sock(sk);
+		err = compat_nf_getsockopt(sk, PF_INET6, optname, optval, &len);
 		if (err >= 0)
 			err = put_user(len, optlen);
 	}
-- 
2.11.0
Other recent patches touching these files
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help