mint0x33/net/xfrm
Khalid Masum a39f456d62 xfrm: Update ipcomp_scratches with NULL when freed
[ Upstream commit 8a04d2fc700f717104bfb95b0f6694e448a4537f ]

Currently if ipcomp_alloc_scratches() fails to allocate memory
ipcomp_scratches holds obsolete address. So when we try to free the
percpu scratches using ipcomp_free_scratches() it tries to vfree non
existent vm area. Described below:

static void * __percpu *ipcomp_alloc_scratches(void)
{
        ...
        scratches = alloc_percpu(void *);
        if (!scratches)
                return NULL;
ipcomp_scratches does not know about this allocation failure.
Therefore holding the old obsolete address.
        ...
}

So when we free,

static void ipcomp_free_scratches(void)
{
        ...
        scratches = ipcomp_scratches;
Assigning obsolete address from ipcomp_scratches

        if (!scratches)
                return;

        for_each_possible_cpu(i)
               vfree(*per_cpu_ptr(scratches, i));
Trying to free non existent page, causing warning: trying to vfree
existent vm area.
        ...
}

Fix this breakage by updating ipcomp_scrtches with NULL when scratches
is freed

Suggested-by: Herbert Xu <herbert@gondor.apana.org.au>
Reported-by: syzbot+5ec9bb042ddfe9644773@syzkaller.appspotmail.com
Tested-by: syzbot+5ec9bb042ddfe9644773@syzkaller.appspotmail.com
Signed-off-by: Khalid Masum <khalid.masum.92@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-10-26 13:17:09 +02:00
..
Kconfig ipsec: select crypto ciphers for xfrm_algo 2019-07-31 07:28:27 +02:00
Makefile
xfrm_algo.c
xfrm_device.c xfrm: enforce validity of offload input flags 2022-03-08 19:01:56 +01:00
xfrm_hash.c
xfrm_hash.h
xfrm_input.c xfrm: Fix oops in xfrm_replay_advance_bmp 2021-02-03 23:22:22 +01:00
xfrm_ipcomp.c xfrm: Update ipcomp_scratches with NULL when freed 2022-10-26 13:17:09 +02:00
xfrm_output.c xfrm: fix a NULL-ptr deref in xfrm_local_error 2020-06-03 08:18:06 +02:00
xfrm_policy.c xfrm: fix refcount leak in __xfrm_policy_check() 2022-09-05 10:25:02 +02:00
xfrm_proc.c
xfrm_replay.c xfrm: Fix ESN sequence number handling for IPsec GSO packets. 2018-05-30 07:52:08 +02:00
xfrm_state.c xfrm: Fix xfrm migrate issues when address family changes 2022-03-23 09:01:34 +01:00
xfrm_sysctl.c
xfrm_user.c xfrm: policy: match with both mark and mask on user interfaces 2022-04-20 09:08:31 +02:00