linux/net/netfilter/ipvs, branch v2.6.35

ipvs: Add missing locking during connection table hashing and unhashing

2010-06-09T14:10:57Z

The code that hashes and unhashes connections from the connection table is missing locking of the connection being modified, which opens up a race condition and results in memory corruption when this race condition is hit. Here is what happens in pretty verbose form: CPU 0 CPU 1 ------------ ------------ An active connection is terminated and we schedule ip_vs_conn_expire() on this CPU to expire this connection. IRQ assignment is changed to this CPU, but the expire timer stays scheduled on the other CPU. New connection from same ip:port comes in right before the timer expires, we find the inactive connection in our connection table and get a reference to it. We proper lock the connection in tcp_state_transition() and read the connection flags in set_tcp_state(). ip_vs_conn_expire() gets called, we unhash the connection from our connection table and remove the hashed flag in ip_vs_conn_unhash(), without proper locking! While still holding proper locks we write the connection flags in set_tcp_state() and this sets the hashed flag again. ip_vs_conn_expire() fails to expire the connection, because the other CPU has incremented the reference count. We try to re-insert the connection into our connection table, but this fails in ip_vs_conn_hash(), because the hashed flag has been set by the other CPU. We re-schedule execution of ip_vs_conn_expire(). Now this connection has the hashed flag set, but isn't actually hashed in our connection table and has a dangling list_head. We drop the reference we held on the connection and schedule the expire timer for timeouting the connection on this CPU. Further packets won't be able to find this connection in our connection table. ip_vs_conn_expire() gets called again, we think it's already hashed, but the list_head is dangling and while removing the connection from our connection table we write to the memory location where this list_head points to. The result will probably be a kernel oops at some other point in time. This race condition is pretty subtle, but it can be triggered remotely. It needs the IRQ assignment change or another circumstance where packets coming from the same ip:port for the same service are being processed on different CPUs. And it involves hitting the exact time at which ip_vs_conn_expire() gets called. It can be avoided by making sure that all packets from one connection are always processed on the same CPU and can be made harder to exploit by changing the connection timeouts to some custom values. Signed-off-by: Sven Wegener Cc: stable@kernel.org Acked-by: Simon Horman Signed-off-by: Patrick McHardy

Merge branch 'master' of /repos/git/net-next-2.6

2010-05-10T16:39:28Z

Conflicts: net/bridge/br_device.c net/bridge/br_forward.c Signed-off-by: Patrick McHardy

net: sk_sleep() helper

2010-04-20T23:37:13Z

Define a new function to return the waitqueue of a "struct sock". static inline wait_queue_head_t *sk_sleep(struct sock *sk) { return sk->sk_sleep; } Change all read occurrences of sk_sleep by a call to this function. Needed for a future RCU conversion. sk_sleep wont be a field directly available. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

Merge branch 'master' of /repos/git/net-next-2.6

2010-04-20T14:02:01Z

Conflicts: Documentation/feature-removal-schedule.txt net/ipv6/netfilter/ip6t_REJECT.c net/netfilter/xt_limit.c Signed-off-by: Patrick McHardy

IPVS: fix potential stack overflow with overly long protocol names

2010-04-08T11:35:47Z

When protocols use very long names, the sprintf calls might overflow the on-stack buffer. No protocol in the kernel does this however. Print the protocol name in the pr_debug statement directly to avoid this. Based on patch by Zhitong Wang Acked-by: Simon Horman Signed-off-by: Patrick McHardy

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32Z

percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo Guess-its-ok-by: Christoph Lameter Cc: Ingo Molnar Cc: Lee Schermerhorn

netfilter: ipvs: use NFPROTO values for NF_HOOK invocation

2010-03-25T15:03:07Z

Semantic patch: // @@ @@ IP_VS_XMIT( -PF_INET6, +NFPROTO_IPV6, ...) @@ @@ IP_VS_XMIT( -PF_INET, +NFPROTO_IPV4, ...) // Signed-off-by: Jan Engelhardt

netfilter: net/netfilter/ipvs/ip_vs_ftp.c: Remove use of NIPQUAD

2010-03-15T17:03:05Z

NIPQUAD has very few uses left. Remove this use and make the code have the identical form of the only other use of "%u,%u,%u,%u,%u,%u" in net/ipv4/netfilter/nf_nat_ftp.c Signed-off-by: Joe Perches Acked-by: Simon Horman Signed-off-by: Patrick McHardy

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-next-2.6

2010-02-26T17:31:09Z

IPVS: ip_vs_lblcr: use list headA

2010-02-26T16:45:14Z

Use list_head rather than a custom list implementation. Signed-off-by: Simon Horman Signed-off-by: Patrick McHardy