From: Sabrina Dubroca <sd@queasysnail.net> stable inclusion from stable-v4.19.323 commit f31398570acf0f0804c644006f7bfa9067106b0a category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IB2SWP CVE: CVE-2024-50142 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 3f0ab59e6537c6a8f9e1b355b48f9c05a76e8563 ] This expands the validation introduced in commit 07bf7908950a ("xfrm: Validate address prefix lengths in the xfrm selector.") syzbot created an SA with usersa.sel.family = AF_UNSPEC usersa.sel.prefixlen_s = 128 usersa.family = AF_INET Because of the AF_UNSPEC selector, verify_newsa_info doesn't put limits on prefixlen_{s,d}. But then copy_from_user_state sets x->sel.family to usersa.family (AF_INET). Do the same conversion in verify_newsa_info before validating prefixlen_{s,d}, since that's how prefixlen is going to be used later on. Reported-by: syzbot+cc39f136925517aed571@syzkaller.appspotmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Antony Antony <antony.antony@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> --- net/xfrm/xfrm_user.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 4fe9651c6331..ff1e14019ff7 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -148,6 +148,7 @@ static int verify_newsa_info(struct xfrm_usersa_info *p, struct nlattr **attrs) { int err; + u16 family = p->sel.family; err = -EINVAL; switch (p->family) { @@ -166,7 +167,10 @@ static int verify_newsa_info(struct xfrm_usersa_info *p, goto out; } - switch (p->sel.family) { + if (!family && !(p->flags & XFRM_STATE_AF_UNSPEC)) + family = p->family; + + switch (family) { case AF_UNSPEC: break; -- 2.25.1