openvswitch: fix flow actions reallocation
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>
OSDN Git Service
