From a68b36a505302b0c9e4446d9f3bfc91c16a201a8 Mon Sep 17 00:00:00 2001 From: Salvatore Bonaccorso Date: Thu, 1 Jun 2017 07:41:53 +0200 Subject: [PATCH] dccp/tcp: do not inherit mc_list from parent (CVE-2017-8890) --- debian/changelog | 1 + ...p-do-not-inherit-mc_list-from-parent.patch | 42 +++++++++++++++++++ debian/patches/series | 1 + 3 files changed, 44 insertions(+) create mode 100644 debian/patches/bugfix/all/dccp-tcp-do-not-inherit-mc_list-from-parent.patch diff --git a/debian/changelog b/debian/changelog index a3169274b..993438341 100644 --- a/debian/changelog +++ b/debian/changelog @@ -412,6 +412,7 @@ linux (4.9.30-1) UNRELEASED; urgency=medium [ Salvatore Bonaccorso ] * tracing: Use strlcpy() instead of strcpy() in __trace_find_cmdline() (CVE-2017-0605) + * dccp/tcp: do not inherit mc_list from parent (CVE-2017-8890) -- Ben Hutchings Mon, 08 May 2017 21:11:08 +0200 diff --git a/debian/patches/bugfix/all/dccp-tcp-do-not-inherit-mc_list-from-parent.patch b/debian/patches/bugfix/all/dccp-tcp-do-not-inherit-mc_list-from-parent.patch new file mode 100644 index 000000000..0498fa9bb --- /dev/null +++ b/debian/patches/bugfix/all/dccp-tcp-do-not-inherit-mc_list-from-parent.patch @@ -0,0 +1,42 @@ +From: Eric Dumazet +Date: Tue, 9 May 2017 06:29:19 -0700 +Subject: dccp/tcp: do not inherit mc_list from parent +Origin: https://git.kernel.org/linus/657831ffc38e30092a2d5f03d385d710eb88b09a +Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2017-8890 + +syzkaller found a way to trigger double frees from ip_mc_drop_socket() + +It turns out that leave a copy of parent mc_list at accept() time, +which is very bad. + +Very similar to commit 8b485ce69876 ("tcp: do not inherit +fastopen_req from parent") + +Initial report from Pray3r, completed by Andrey one. +Thanks a lot to them ! + +Signed-off-by: Eric Dumazet +Reported-by: Pray3r +Reported-by: Andrey Konovalov +Tested-by: Andrey Konovalov +Signed-off-by: David S. Miller +--- + net/ipv4/inet_connection_sock.c | 2 ++ + 1 file changed, 2 insertions(+) + +diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c +index 5e313c1..1054d33 100644 +--- a/net/ipv4/inet_connection_sock.c ++++ b/net/ipv4/inet_connection_sock.c +@@ -794,6 +794,8 @@ struct sock *inet_csk_clone_lock(const struct sock *sk, + /* listeners have SOCK_RCU_FREE, not the children */ + sock_reset_flag(newsk, SOCK_RCU_FREE); + ++ inet_sk(newsk)->mc_list = NULL; ++ + newsk->sk_mark = inet_rsk(req)->ir_mark; + atomic64_set(&newsk->sk_cookie, + atomic64_read(&inet_rsk(req)->ir_cookie)); +-- +2.1.4 + diff --git a/debian/patches/series b/debian/patches/series index d8243e45a..30fb4e621 100644 --- a/debian/patches/series +++ b/debian/patches/series @@ -105,6 +105,7 @@ features/all/securelevel/arm64-add-kernel-config-option-to-set-securelevel-wh.pa debian/i386-686-pae-pci-set-pci-nobios-by-default.patch debian/time-mark-timer_stats-as-broken.patch bugfix/all/tracing-Use-strlcpy-instead-of-strcpy-in-__trace_fin.patch +bugfix/all/dccp-tcp-do-not-inherit-mc_list-from-parent.patch # Fix exported symbol versions bugfix/ia64/revert-ia64-move-exports-to-definitions.patch