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| author | Khalid Masum <khalid.masum.92@gmail.com> | 2022-09-01 10:12:10 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-10-26 14:25:46 +0300 |
| commit | be81c44242b20fc3bdcc73480ef8aaee56f5d0b6 (patch) | |
| tree | ca495e4ade05a946f4f65cfb3c4807689fe28e39 /net/xfrm | |
| parent | 9661724f6206bd606ecf13acada676a9975d230b (diff) | |
| download | linux-be81c44242b20fc3bdcc73480ef8aaee56f5d0b6.tar.xz | |
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>
Diffstat (limited to 'net/xfrm')
| -rw-r--r-- | net/xfrm/xfrm_ipcomp.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c index 0814320472f1..24ac6805275e 100644 --- a/net/xfrm/xfrm_ipcomp.c +++ b/net/xfrm/xfrm_ipcomp.c @@ -212,6 +212,7 @@ static void ipcomp_free_scratches(void) vfree(*per_cpu_ptr(scratches, i)); free_percpu(scratches); + ipcomp_scratches = NULL; } static void * __percpu *ipcomp_alloc_scratches(void) |