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authorMark Brown <broonie@kernel.org>2016-02-05 19:31:55 +0000
committerMark Brown <broonie@kernel.org>2016-02-05 19:31:55 +0000
commit34f6d2c9d12a97271d55c7b204443b2da9e6c29e (patch)
tree2e6b1d1c4db95041fe2590d11a45cdb567e00360 /net/unix/af_unix.c
parentafd2ff9b7e1b367172f18ba7f693dfb62bdcb2dc (diff)
parentf1ab5eafa3625b41c74326a1994a820ff805d5b2 (diff)
Merge tag 'v4.4.1' into linux-linaro-lsk-v4.4
This is the 4.4.1 stable release # gpg: Signature made Sun 31 Jan 2016 19:29:43 GMT using RSA key ID 6092693E # gpg: Good signature from "Greg Kroah-Hartman (Linux kernel stable release signing key) <greg@kroah.com>" # gpg: WARNING: This key is not certified with a trusted signature! # gpg: There is no indication that the signature belongs to the owner. # Primary key fingerprint: 647F 2865 4894 E3BD 4571 99BE 38DB BDC8 6092 693E
Diffstat (limited to 'net/unix/af_unix.c')
-rw-r--r--net/unix/af_unix.c24
1 files changed, 20 insertions, 4 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index ef05cd9403d4..e3f85bc8b135 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1513,6 +1513,21 @@ static void unix_destruct_scm(struct sk_buff *skb)
sock_wfree(skb);
}
+/*
+ * The "user->unix_inflight" variable is protected by the garbage
+ * collection lock, and we just read it locklessly here. If you go
+ * over the limit, there might be a tiny race in actually noticing
+ * it across threads. Tough.
+ */
+static inline bool too_many_unix_fds(struct task_struct *p)
+{
+ struct user_struct *user = current_user();
+
+ if (unlikely(user->unix_inflight > task_rlimit(p, RLIMIT_NOFILE)))
+ return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN);
+ return false;
+}
+
#define MAX_RECURSION_LEVEL 4
static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
@@ -1521,6 +1536,9 @@ static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
unsigned char max_level = 0;
int unix_sock_count = 0;
+ if (too_many_unix_fds(current))
+ return -ETOOMANYREFS;
+
for (i = scm->fp->count - 1; i >= 0; i--) {
struct sock *sk = unix_get_socket(scm->fp->fp[i]);
@@ -1542,10 +1560,8 @@ static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
if (!UNIXCB(skb).fp)
return -ENOMEM;
- if (unix_sock_count) {
- for (i = scm->fp->count - 1; i >= 0; i--)
- unix_inflight(scm->fp->fp[i]);
- }
+ for (i = scm->fp->count - 1; i >= 0; i--)
+ unix_inflight(scm->fp->fp[i]);
return max_level;
}