diff --git a/debian/changelog b/debian/changelog index 77968995f..88b43e16a 100644 --- a/debian/changelog +++ b/debian/changelog @@ -4,6 +4,7 @@ linux (4.19.98-1+deb10u1) UNRELEASED; urgency=medium * do_last(): fetch directory ->i_mode and ->i_uid before it's too late (CVE-2020-8428) * vfs: fix do_last() regression + * vhost: Check docket sk_family instead of call getname (CVE-2020-10942) -- Salvatore Bonaccorso Sun, 26 Apr 2020 20:32:58 +0200 diff --git a/debian/patches/bugfix/all/vhost-Check-docket-sk_family-instead-of-call-getname.patch b/debian/patches/bugfix/all/vhost-Check-docket-sk_family-instead-of-call-getname.patch new file mode 100644 index 000000000..66f3c1dc6 --- /dev/null +++ b/debian/patches/bugfix/all/vhost-Check-docket-sk_family-instead-of-call-getname.patch @@ -0,0 +1,57 @@ +From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= +Date: Fri, 21 Feb 2020 12:06:56 +0100 +Subject: vhost: Check docket sk_family instead of call getname +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit +Origin: https://git.kernel.org/linus/42d84c8490f9f0931786f1623191fcab397c3d64 +Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2020-10942 + +Doing so, we save one call to get data we already have in the struct. + +Also, since there is no guarantee that getname use sockaddr_ll +parameter beyond its size, we add a little bit of security here. +It should do not do beyond MAX_ADDR_LEN, but syzbot found that +ax25_getname writes more (72 bytes, the size of full_sockaddr_ax25, +versus 20 + 32 bytes of sockaddr_ll + MAX_ADDR_LEN in syzbot repro). + +Fixes: 3a4d5c94e9593 ("vhost_net: a kernel-level virtio server") +Reported-by: syzbot+f2a62d07a5198c819c7b@syzkaller.appspotmail.com +Signed-off-by: Eugenio PĂ©rez +Acked-by: Michael S. Tsirkin +Signed-off-by: David S. Miller +--- + drivers/vhost/net.c | 10 +--------- + 1 file changed, 1 insertion(+), 9 deletions(-) + +diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c +index e158159671fa..18e205eeb9af 100644 +--- a/drivers/vhost/net.c ++++ b/drivers/vhost/net.c +@@ -1414,10 +1414,6 @@ static int vhost_net_release(struct inode *inode, struct file *f) + + static struct socket *get_raw_socket(int fd) + { +- struct { +- struct sockaddr_ll sa; +- char buf[MAX_ADDR_LEN]; +- } uaddr; + int r; + struct socket *sock = sockfd_lookup(fd, &r); + +@@ -1430,11 +1426,7 @@ static struct socket *get_raw_socket(int fd) + goto err; + } + +- r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa, 0); +- if (r < 0) +- goto err; +- +- if (uaddr.sa.sll_family != AF_PACKET) { ++ if (sock->sk->sk_family != AF_PACKET) { + r = -EPFNOSUPPORT; + goto err; + } +-- +2.26.2 + diff --git a/debian/patches/series b/debian/patches/series index df2599a63..877f0e53a 100644 --- a/debian/patches/series +++ b/debian/patches/series @@ -307,6 +307,7 @@ bugfix/all/wimax-i2400-fix-memory-leak-in-i2400m_op_rfkill_sw_toggle.patch bugfix/x86/KVM-nVMX-Don-t-emulate-instructions-in-guest-mode.patch bugfix/all/do_last-fetch-directory-i_mode-and-i_uid-before-it-s.patch bugfix/all/vfs-fix-do_last-regression.patch +bugfix/all/vhost-Check-docket-sk_family-instead-of-call-getname.patch # Backported change to provide boot-time entropy bugfix/all/random-try-to-actively-add-entropy-rather-than-passi.patch