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authorHannes Frederic Sowa <hannes@stressinduktion.org>2016-02-03 02:11:03 +0100
committerDavid S. Miller <davem@davemloft.net>2016-02-08 16:30:42 +0100
commit415e3d3e90ce9e18727e8843ae343eda5a58fad6 (patch)
tree529751765d40af6f6cfcafdc1c92b1dcafb5c8da /net/unix/af_unix.c
parentupdate be2net maintainers' email addresses (diff)
downloadlinux-415e3d3e90ce9e18727e8843ae343eda5a58fad6.tar.xz
linux-415e3d3e90ce9e18727e8843ae343eda5a58fad6.zip
unix: correctly track in-flight fds in sending process user_struct
The commit referenced in the Fixes tag incorrectly accounted the number of in-flight fds over a unix domain socket to the original opener of the file-descriptor. This allows another process to arbitrary deplete the original file-openers resource limit for the maximum of open files. Instead the sending processes and its struct cred should be credited. To do so, we add a reference counted struct user_struct pointer to the scm_fp_list and use it to account for the number of inflight unix fds. Fixes: 712f4aad406bb1 ("unix: properly account for FDs passed over unix sockets") Reported-by: David Herrmann <dh.herrmann@gmail.com> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/unix/af_unix.c')
-rw-r--r--net/unix/af_unix.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 49d5093eb055..29be035f9c65 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1496,7 +1496,7 @@ static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
UNIXCB(skb).fp = NULL;
for (i = scm->fp->count-1; i >= 0; i--)
- unix_notinflight(scm->fp->fp[i]);
+ unix_notinflight(scm->fp->user, scm->fp->fp[i]);
}
static void unix_destruct_scm(struct sk_buff *skb)
@@ -1561,7 +1561,7 @@ static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
return -ENOMEM;
for (i = scm->fp->count - 1; i >= 0; i--)
- unix_inflight(scm->fp->fp[i]);
+ unix_inflight(scm->fp->user, scm->fp->fp[i]);
return max_level;
}