4.9-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 32bf94fb5c2ec4ec842152d0e5937cd4bb6738fa ]
XFRM mode parameters passed as part of the user templates in the IP_XFRM_POLICY are never properly validated. Passing values other than valid XFRM modes can cause stack-out-of-bounds reads to occur later in the XFRM processing:
[ 140.535608] ================================================================ [ 140.543058] BUG: KASAN: stack-out-of-bounds in xfrm_state_find+0x17e4/0x1cc4 [ 140.550306] Read of size 4 at addr ffffffc0238a7a58 by task repro/5148 [ 140.557369] [ 140.558927] Call trace: [ 140.558936] dump_backtrace+0x0/0x388 [ 140.558940] show_stack+0x24/0x30 [ 140.558946] __dump_stack+0x24/0x2c [ 140.558949] dump_stack+0x8c/0xd0 [ 140.558956] print_address_description+0x74/0x234 [ 140.558960] kasan_report+0x240/0x264 [ 140.558963] __asan_report_load4_noabort+0x2c/0x38 [ 140.558967] xfrm_state_find+0x17e4/0x1cc4 [ 140.558971] xfrm_resolve_and_create_bundle+0x40c/0x1fb8 [ 140.558975] xfrm_lookup+0x238/0x1444 [ 140.558977] xfrm_lookup_route+0x48/0x11c [ 140.558984] ip_route_output_flow+0x88/0xc4 [ 140.558991] raw_sendmsg+0xa74/0x266c [ 140.558996] inet_sendmsg+0x258/0x3b0 [ 140.559002] sock_sendmsg+0xbc/0xec [ 140.559005] SyS_sendto+0x3a8/0x5a8 [ 140.559008] el0_svc_naked+0x34/0x38 [ 140.559009] [ 140.592245] page dumped because: kasan: bad access detected [ 140.597981] page_owner info is not active (free page?) [ 140.603267] [ 140.653503] ================================================================
Signed-off-by: Sean Tranchetti stranche@codeaurora.org Signed-off-by: Steffen Klassert steffen.klassert@secunet.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/xfrm/xfrm_user.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index b7ac834a6091..026770884d46 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -1412,6 +1412,9 @@ static int validate_tmpl(int nr, struct xfrm_user_tmpl *ut, u16 family) (ut[i].family != prev_family)) return -EINVAL;
+ if (ut[i].mode >= XFRM_MODE_MAX) + return -EINVAL; + prev_family = ut[i].family;
switch (ut[i].family) {