The flow action buffer can be resized if it's not big enough to contain all the requested flow actions. However, this resize doesn't take into account the new requested size, the buffer is only increased by a factor of 2x. This might be not enough to contain the new data, causing a buffer overflow, for example: [ 42.044472] ============================================================================= [ 42.045608] BUG kmalloc-96 (Not tainted): Redzone overwritten [ 42.046415] ----------------------------------------------------------------------------- [ 42.047715] Disabling lock debugging due to kernel taint [ 42.047716] INFO: 0x8bf2c4a5-0x720c0928. First byte 0x0 instead of 0xcc [ 42.048677] INFO: Slab 0xbc6d2040 objects=29 used=18 fp=0xdc07dec4 flags=0x2808101 [ 42.049743] INFO: Object 0xd53a3464 @offset=2528 fp=0xccdcdebb [ 42.050747] Redzone 76f1b237: cc cc cc cc cc cc cc cc ........ [ 42.051839] Object d53a3464: 6b 6b 6b 6b 6b 6b 6b 6b 0c 00 00 00 6c 00 00 00 kkkkkkkk....l... [ 42.053015] Object f49a30cc: 6c 00 0c 00 00 00 00 00 00 00 00 03 78 a3 15 f6 l...........x... [ 42.054203] Object acfe4220: 20 00 02 00 ff ff ff ff 00 00 00 00 00 00 00 00 ............... [ 42.055370] Object 21024e91: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 42.056541] Object 070e04c3: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 42.057797] Object 948a777a: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 42.059061] Redzone 8bf2c4a5: 00 00 00 00 .... [ 42.060189] Padding a681b46e: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ Fix by making sure the new buffer is properly resized to contain all the requested data. BugLink: https://bugs.launchpad.net/bugs/1813244 Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Acked-by: Pravin B Shelar <pshelar@ovn.org> Signed-off-by: David S. Miller <davem@davemloft.net>
nla_nest_start may fail and thus deserves a check. The fix returns -EMSGSIZE when it fails. Signed-off-by: Kangjie Lu <kjlu@umn.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
upcall is dereferenced even when genlmsg_put fails. The fix goto out to avoid the NULL pointer dereference in this case. Signed-off-by: Kangjie Lu <kjlu@umn.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
Patch series "generic radix trees; drop flex arrays". This patch (of 7): There was no real need for this code to be using flexarrays, it's just implementing a hash table - ideally it would be using rhashtables, but that conversion would be significantly more complicated. Link: http://lkml.kernel.org/r/20181217131929.11727-2-kent.overstreet@gmail.com Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Reviewed-by: Matthew Wilcox <willy@infradead.org> Cc: Pravin B Shelar <pshelar@ovn.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Eric Paris <eparis@parisplace.org> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Shaohua Li <shli@kernel.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The l3proto name is gone, its header file is the last trace. While at it, also remove nf_nat_core.h, its very small and all users include nf_nat.h too. before: text data bss dec hex filename 22948 1612 4136 28696 7018 nf_nat.ko after removal of l3proto register/unregister functions: text data bss dec hex filename 22196 1516 4136 27848 6cc8 nf_nat.ko checkpatch complains about overly long lines, but line breaks do not make things more readable and the line length gets smaller here, not larger. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
before:
text data bss dec hex filename
16566 1576 4136 22278 5706 nf_nat.ko
3598 844 0 4442 115a nf_nat_ipv6.ko
3187 844 0 4031 fbf nf_nat_ipv4.ko
after:
text data bss dec hex filename
22948 1612 4136 28696 7018 nf_nat.ko
... with ipv4/v6 nat now provided directly via nf_nat.ko.
Also changes:
ret = nf_nat_ipv4_fn(priv, skb, state);
if (ret != NF_DROP && ret != NF_STOLEN &&
into
if (ret != NF_ACCEPT)
return ret;
everywhere.
The nat hooks never should return anything other than
ACCEPT or DROP (and the latter only in rare error cases).
The original code uses multi-line ANDing including assignment-in-if:
if (ret != NF_DROP && ret != NF_STOLEN &&
!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) &&
(ct = nf_ct_get(skb, &ctinfo)) != NULL) {
I removed this while moving, breaking those in separate conditionals
and moving the assignments into extra lines.
checkpatch still generates some warnings:
1. Overly long lines (of moved code).
Breaking them is even more ugly. so I kept this as-is.
2. use of extern function declarations in a .c file.
This is necessary evil, we must call
nf_nat_l3proto_register() from the nat core now.
All l3proto related functions are removed later in this series,
those prototypes are then removed as well.
v2: keep empty nf_nat_ipv6_csum_update stub for CONFIG_IPV6=n case.
v3: remove IS_ENABLED(NF_NAT_IPV4/6) tests, NF_NAT_IPVx toggles
are removed here.
v4: also get rid of the assignments in conditionals.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS updates for your net-next tree:
1) Introduce a hashtable to speed up object lookups, from Florian Westphal.
2) Make direct calls to built-in extension, also from Florian.
3) Call helper before confirming the conntrack as it used to be originally,
from Florian.
4) Call request_module() to autoload br_netfilter when physdev is used
to relax the dependency, also from Florian.
5) Allow to insert rules at a given position ID that is internal to the
batch, from Phil Sutter.
6) Several patches to replace conntrack indirections by direct calls,
and to reduce modularization, from Florian. This also includes
several follow up patches to deal with minor fallout from this
rework.
7) Use RCU from conntrack gre helper, from Florian.
8) GRE conntrack module becomes built-in into nf_conntrack, from Florian.
9) Replace nf_ct_invert_tuplepr() by calls to nf_ct_invert_tuple(),
from Florian.
10) Unify sysctl handling at the core of nf_conntrack, from Florian.
11) Provide modparam to register conntrack hooks.
12) Allow to match on the interface kind string, from wenxu.
13) Remove several exported symbols, not required anymore now after
a bit of de-modulatization work has been done, from Florian.
14) Remove built-in map support in the hash extension, this can be
done with the existing userspace infrastructure, from laura.
15) Remove indirection to calculate checksums in IPVS, from Matteo Croce.
16) Use call wrappers for indirection in IPVS, also from Matteo.
17) Remove superfluous __percpu parameter in nft_counter, patch from
Luc Van Oostenryck.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Completely minor snmp doc conflict. Signed-off-by: David S. Miller <davem@davemloft.net>
after removal of the packet and invert function pointers, several places do not need to lookup the l4proto structure anymore. Remove those lookups. The function nf_ct_invert_tuplepr becomes redundant, replace it with nf_ct_invert_tuple everywhere. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
One of the more common cases of allocation size calculations is finding the
size of a structure that has a zero-sized array at the end, along with memory
for some number of elements for that array. For example:
struct foo {
int stuff;
struct boo entry[];
};
instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can now
use the new struct_size() helper:
instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>