unix: correctly track in-flight fds in sending process user_struct
Fixes a regression caused by the previous partial fix for CVE-2013-4312. Ignore ABI changes as we never build unix sockets as a module and nothing OOT should use the scm functions.
This commit is contained in:
parent
a47af1b9f9
commit
5810ec7828
|
@ -1,8 +1,13 @@
|
|||
linux (4.4.2-4) UNRELEASED; urgency=medium
|
||||
|
||||
[ Roger Shimizu ]
|
||||
* [armhf] dts: imx6dlq-wandboard-revb1: use unique model id
|
||||
(Closes: #813881).
|
||||
|
||||
[ Ben Hutchings ]
|
||||
* unix: correctly track in-flight fds in sending process user_struct
|
||||
(regression in 4.3.3-6)
|
||||
|
||||
-- Roger Shimizu <rogershimizu@gmail.com> Wed, 24 Feb 2016 01:30:38 +0900
|
||||
|
||||
linux (4.4.2-3) unstable; urgency=medium
|
||||
|
|
|
@ -1,5 +1,11 @@
|
|||
[abi]
|
||||
abiname: 1
|
||||
ignore-changes:
|
||||
# Not used by OOT modules
|
||||
__scm_destroy
|
||||
__scm_send
|
||||
scm_detach_fds
|
||||
scm_fp_dup
|
||||
|
||||
[base]
|
||||
arches:
|
||||
|
|
155
debian/patches/bugfix/all/unix-correctly-track-in-flight-fds-in-sending-process-user_struct.patch
vendored
Normal file
155
debian/patches/bugfix/all/unix-correctly-track-in-flight-fds-in-sending-process-user_struct.patch
vendored
Normal file
|
@ -0,0 +1,155 @@
|
|||
From: Hannes Frederic Sowa <hannes@stressinduktion.org>
|
||||
Date: Wed, 3 Feb 2016 02:11:03 +0100
|
||||
Subject: unix: correctly track in-flight fds in sending process user_struct
|
||||
Origin: https://git.kernel.org/linus/415e3d3e90ce9e18727e8843ae343eda5a58fad6
|
||||
|
||||
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>
|
||||
---
|
||||
include/net/af_unix.h | 4 ++--
|
||||
include/net/scm.h | 1 +
|
||||
net/core/scm.c | 7 +++++++
|
||||
net/unix/af_unix.c | 4 ++--
|
||||
net/unix/garbage.c | 8 ++++----
|
||||
5 files changed, 16 insertions(+), 8 deletions(-)
|
||||
|
||||
diff --git a/include/net/af_unix.h b/include/net/af_unix.h
|
||||
index 2a91a0561a47..9b4c418bebd8 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>
|
||||
|
||||
-void unix_inflight(struct file *fp);
|
||||
-void unix_notinflight(struct file *fp);
|
||||
+void unix_inflight(struct user_struct *user, struct file *fp);
|
||||
+void unix_notinflight(struct user_struct *user, struct file *fp);
|
||||
void unix_gc(void);
|
||||
void wait_for_unix_gc(void);
|
||||
struct sock *unix_get_socket(struct file *filp);
|
||||
diff --git a/include/net/scm.h b/include/net/scm.h
|
||||
index 262532d111f5..59fa93c01d2a 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];
|
||||
};
|
||||
|
||||
diff --git a/net/core/scm.c b/net/core/scm.c
|
||||
index 14596fb37172..2696aefdc148 100644
|
||||
--- a/net/core/scm.c
|
||||
+++ b/net/core/scm.c
|
||||
@@ -87,6 +87,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
|
||||
*fplp = fpl;
|
||||
fpl->count = 0;
|
||||
fpl->max = SCM_MAX_FD;
|
||||
+ fpl->user = NULL;
|
||||
}
|
||||
fpp = &fpl->fp[fpl->count];
|
||||
|
||||
@@ -107,6 +108,10 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
|
||||
*fpp++ = file;
|
||||
fpl->count++;
|
||||
}
|
||||
+
|
||||
+ if (!fpl->user)
|
||||
+ fpl->user = get_uid(current_user());
|
||||
+
|
||||
return num;
|
||||
}
|
||||
|
||||
@@ -119,6 +124,7 @@ void __scm_destroy(struct scm_cookie *scm)
|
||||
scm->fp = NULL;
|
||||
for (i=fpl->count-1; i>=0; i--)
|
||||
fput(fpl->fp[i]);
|
||||
+ free_uid(fpl->user);
|
||||
kfree(fpl);
|
||||
}
|
||||
}
|
||||
@@ -336,6 +342,7 @@ struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl)
|
||||
for (i = 0; i < fpl->count; i++)
|
||||
get_file(fpl->fp[i]);
|
||||
new_fpl->max = new_fpl->count;
|
||||
+ new_fpl->user = get_uid(fpl->user);
|
||||
}
|
||||
return new_fpl;
|
||||
}
|
||||
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;
|
||||
}
|
||||
|
||||
diff --git a/net/unix/garbage.c b/net/unix/garbage.c
|
||||
index 8fcdc2283af5..6a0d48525fcf 100644
|
||||
--- a/net/unix/garbage.c
|
||||
+++ b/net/unix/garbage.c
|
||||
@@ -116,7 +116,7 @@ struct sock *unix_get_socket(struct file *filp)
|
||||
* descriptor if it is for an AF_UNIX socket.
|
||||
*/
|
||||
|
||||
-void unix_inflight(struct file *fp)
|
||||
+void unix_inflight(struct user_struct *user, struct file *fp)
|
||||
{
|
||||
struct sock *s = unix_get_socket(fp);
|
||||
|
||||
@@ -133,11 +133,11 @@ void unix_inflight(struct file *fp)
|
||||
}
|
||||
unix_tot_inflight++;
|
||||
}
|
||||
- fp->f_cred->user->unix_inflight++;
|
||||
+ user->unix_inflight++;
|
||||
spin_unlock(&unix_gc_lock);
|
||||
}
|
||||
|
||||
-void unix_notinflight(struct file *fp)
|
||||
+void unix_notinflight(struct user_struct *user, struct file *fp)
|
||||
{
|
||||
struct sock *s = unix_get_socket(fp);
|
||||
|
||||
@@ -152,7 +152,7 @@ void unix_notinflight(struct file *fp)
|
||||
list_del_init(&u->link);
|
||||
unix_tot_inflight--;
|
||||
}
|
||||
- fp->f_cred->user->unix_inflight--;
|
||||
+ user->unix_inflight--;
|
||||
spin_unlock(&unix_gc_lock);
|
||||
}
|
||||
|
|
@ -133,3 +133,4 @@ bugfix/all/iff_no_queue-fix-for-drivers-not-calling-ether_setup.patch
|
|||
bugfix/arm/net-mv643xx_eth-fix-packet-corruption-with-tso-and-t.patch
|
||||
bugfix/x86/x86-efi-bgrt-fix-kernel-panic-when-mapping-bgrt-data.patch
|
||||
bugfix/x86/x86-efi-bgrt-replace-early_memremap-with-memremap.patch
|
||||
bugfix/all/unix-correctly-track-in-flight-fds-in-sending-process-user_struct.patch
|
||||
|
|
Loading…
Reference in New Issue