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| author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2016-02-03 02:11:03 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-03-03 15:06:20 -0800 |
| commit | 341f09c01a7f26a030f3bedb08e4ce91e3ca24d3 (patch) | |
| tree | ae6b04fcf9a4ecf2c2196297be7f2c9711018ae7 /include | |
| parent | 59ae7b1c13bd615b09bff9d03aaa335559af604a (diff) | |
| download | lwn-341f09c01a7f26a030f3bedb08e4ce91e3ca24d3.tar.gz lwn-341f09c01a7f26a030f3bedb08e4ce91e3ca24d3.zip | |
unix: correctly track in-flight fds in sending process user_struct
commit 415e3d3e90ce9e18727e8843ae343eda5a58fad6 upstream.
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>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/af_unix.h | 4 | ||||
| -rw-r--r-- | include/net/scm.h | 1 |
2 files changed, 3 insertions, 2 deletions
diff --git a/include/net/af_unix.h b/include/net/af_unix.h index 686760024572..6278e4d32612 100644 --- a/include/net/af_unix.h +++ b/include/net/af_unix.h @@ -6,8 +6,8 @@ #include <linux/mutex.h> #include <net/sock.h> -extern void unix_inflight(struct file *fp); -extern void unix_notinflight(struct file *fp); +extern void unix_inflight(struct user_struct *user, struct file *fp); +extern void unix_notinflight(struct user_struct *user, struct file *fp); extern void unix_gc(void); extern void wait_for_unix_gc(void); extern struct sock *unix_get_socket(struct file *filp); diff --git a/include/net/scm.h b/include/net/scm.h index 8de2d37d2077..d00cd43a990c 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -21,6 +21,7 @@ struct scm_creds { struct scm_fp_list { short count; short max; + struct user_struct *user; struct file *fp[SCM_MAX_FD]; }; |