This is a note to let you know that I've just added the patch titled
Revert "exec: avoid RLIMIT_STACK races with prlimit()"
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
revert-exec-avoid-rlimit_stack-races-with-prlimit.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 779f4e1c6c7c661db40dfebd6dd6bda7b5f88aa3 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@xxxxxxxxxxxx>
Date: Tue, 12 Dec 2017 11:28:38 -0800
Subject: Revert "exec: avoid RLIMIT_STACK races with prlimit()"
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From: Kees Cook <keescook@xxxxxxxxxxxx>
commit 779f4e1c6c7c661db40dfebd6dd6bda7b5f88aa3 upstream.
This reverts commit 04e35f4495dd560db30c25efca4eecae8ec8c375.
SELinux runs with secureexec for all non-"noatsecure" domain transitions,
which means lots of processes end up hitting the stack hard-limit change
that was introduced in order to fix a race with prlimit(). That race fix
will need to be redesigned.
Reported-by: Laura Abbott <labbott@xxxxxxxxxx>
Reported-by: Tomáš Trnka <trnka@xxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/exec.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1340,15 +1340,10 @@ void setup_new_exec(struct linux_binprm
* avoid bad behavior from the prior rlimits. This has to
* happen before arch_pick_mmap_layout(), which examines
* RLIMIT_STACK, but after the point of no return to avoid
- * races from other threads changing the limits. This also
- * must be protected from races with prlimit() calls.
+ * needing to clean up the change on failure.
*/
- task_lock(current->group_leader);
if (current->signal->rlim[RLIMIT_STACK].rlim_cur > _STK_LIM)
current->signal->rlim[RLIMIT_STACK].rlim_cur = _STK_LIM;
- if (current->signal->rlim[RLIMIT_STACK].rlim_max > _STK_LIM)
- current->signal->rlim[RLIMIT_STACK].rlim_max = _STK_LIM;
- task_unlock(current->group_leader);
}
arch_pick_mmap_layout(current->mm);
Patches currently in stable-queue which might be from keescook@xxxxxxxxxxxx are
queue-4.14/revert-exec-avoid-rlimit_stack-races-with-prlimit.patch
queue-4.14/string.h-workaround-for-increased-stack-usage.patch
queue-4.14/arm64-fix-config_debug_wx-address-reporting.patch