From: Sabrina Dubroca <sd@queasysnail.net> stable inclusion from stable-v6.6.109 commit 0baf92d0b1590b903c1f4ead75e61715e50e8146 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/13525 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit cd8ae32e4e4652db55bce6b9c79267d8946765a9 ] x->id.spi == 0 means "no SPI assigned", but since commit 94f39804d891 ("xfrm: Duplicate SPI Handling"), we now create states and add them to the byspi list with this value. __xfrm_state_delete doesn't remove those states from the byspi list, since they shouldn't be there, and this shows up as a UAF the next time we go through the byspi list. Reported-by: syzbot+a25ee9d20d31e483ba7b@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=a25ee9d20d31e483ba7b Fixes: 94f39804d891 ("xfrm: Duplicate SPI Handling") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> --- net/xfrm/xfrm_state.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c index b36eedad21f1..4efbc0b22378 100644 --- a/net/xfrm/xfrm_state.c +++ b/net/xfrm/xfrm_state.c @@ -2287,6 +2287,8 @@ int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high, for (h = 0; h < range; h++) { u32 spi = (low == high) ? low : get_random_u32_inclusive(low, high); + if (spi == 0) + goto next; newspi = htonl(spi); spin_lock_bh(&net->xfrm.xfrm_state_lock); @@ -2302,6 +2304,7 @@ int xfrm_alloc_spi(struct xfrm_state *x, u32 low, u32 high, xfrm_state_put(x0); spin_unlock_bh(&net->xfrm.xfrm_state_lock); +next: if (signal_pending(current)) { err = -ERESTARTSYS; goto unlock; -- 2.25.1