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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-09-12 12:58:01 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-09-12 12:58:01 -0700 |
| commit | ef2e9a563b0cd7965e2a1263125dcbb1c86aa6cc (patch) | |
| tree | 7ac185fdcc40791fcd31f32836082ca4a267b57f | |
| parent | 4f8b0a5b3f7e5f03b188de9025b60c15559790f9 (diff) | |
| parent | e839317900e9f13c83d8711d684de88c625b307a (diff) | |
| download | linux-ef2e9a563b0cd7965e2a1263125dcbb1c86aa6cc.tar.bz2 | |
Merge tag 'seccomp-v5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull seccomp fixes from Kees Cook:
"This fixes a rare race condition in seccomp when using TSYNC and
USER_NOTIF together where a memory allocation would not get freed
(found by syzkaller, fixed by Tycho).
Additionally updates Tycho's MAINTAINERS and .mailmap entries for his
new address"
* tag 'seccomp-v5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
seccomp: don't leave dangling ->notif if file allocation fails
mailmap, MAINTAINERS: move to tycho.pizza
seccomp: don't leak memory when filter install races
| -rw-r--r-- | .mailmap | 1 | ||||
| -rw-r--r-- | MAINTAINERS | 2 | ||||
| -rw-r--r-- | kernel/seccomp.c | 24 |
3 files changed, 20 insertions, 7 deletions
@@ -308,6 +308,7 @@ Tony Luck <tony.luck@intel.com> TripleX Chung <xxx.phy@gmail.com> <triplex@zh-kernel.org> TripleX Chung <xxx.phy@gmail.com> <zhongyu@18mail.cn> Tsuneo Yoshioka <Tsuneo.Yoshioka@f-secure.com> +Tycho Andersen <tycho@tycho.pizza> <tycho@tycho.ws> Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de> Uwe Kleine-König <ukl@pengutronix.de> Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com> diff --git a/MAINTAINERS b/MAINTAINERS index 5e6e36542c62..c44b111f64d8 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9800,7 +9800,7 @@ F: drivers/scsi/53c700* LEAKING_ADDRESSES M: Tobin C. Harding <me@tobin.cc> -M: Tycho Andersen <tycho@tycho.ws> +M: Tycho Andersen <tycho@tycho.pizza> L: kernel-hardening@lists.openwall.com S: Maintained T: git git://git.kernel.org/pub/scm/linux/kernel/git/tobin/leaks.git diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 3ee59ce0a323..676d4af62103 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -1109,13 +1109,18 @@ out: } #ifdef CONFIG_SECCOMP_FILTER -static int seccomp_notify_release(struct inode *inode, struct file *file) +static void seccomp_notify_free(struct seccomp_filter *filter) +{ + kfree(filter->notif); + filter->notif = NULL; +} + +static void seccomp_notify_detach(struct seccomp_filter *filter) { - struct seccomp_filter *filter = file->private_data; struct seccomp_knotif *knotif; if (!filter) - return 0; + return; mutex_lock(&filter->notify_lock); @@ -1139,9 +1144,15 @@ static int seccomp_notify_release(struct inode *inode, struct file *file) complete(&knotif->ready); } - kfree(filter->notif); - filter->notif = NULL; + seccomp_notify_free(filter); mutex_unlock(&filter->notify_lock); +} + +static int seccomp_notify_release(struct inode *inode, struct file *file) +{ + struct seccomp_filter *filter = file->private_data; + + seccomp_notify_detach(filter); __put_seccomp_filter(filter); return 0; } @@ -1488,7 +1499,7 @@ static struct file *init_listener(struct seccomp_filter *filter) out_notif: if (IS_ERR(ret)) - kfree(filter->notif); + seccomp_notify_free(filter); out: return ret; } @@ -1581,6 +1592,7 @@ out_put_fd: listener_f->private_data = NULL; fput(listener_f); put_unused_fd(listener); + seccomp_notify_detach(prepared); } else { fd_install(listener, listener_f); ret = listener; |