This is a note to let you know that I've just added the patch titled
target/user: Fix use-after-free of tcmu_cmds if they are expired
to the 4.4-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:
target-user-fix-use-after-free-of-tcmu_cmds-if-they-are-expired.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From d0905ca757bc40bd1ebc261a448a521b064777d7 Mon Sep 17 00:00:00 2001
From: Andy Grover <agrover@xxxxxxxxxx>
Date: Mon, 21 Nov 2016 16:35:30 -0800
Subject: target/user: Fix use-after-free of tcmu_cmds if they are expired
From: Andy Grover <agrover@xxxxxxxxxx>
commit d0905ca757bc40bd1ebc261a448a521b064777d7 upstream.
Don't free the cmd in tcmu_check_expired_cmd, it's still referenced by
an entry in our cmd_id->cmd idr. If userspace ever resumes processing,
tcmu_handle_completions() will use the now-invalid cmd pointer.
Instead, don't free cmd. It will be freed by tcmu_handle_completion() if
userspace ever recovers, or tcmu_free_device if not.
Reported-by: Bryant G Ly <bgly@xxxxxxxxxx>
Tested-by: Bryant G Ly <bgly@xxxxxxxxxx>
Signed-off-by: Andy Grover <agrover@xxxxxxxxxx>
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/target/target_core_user.c | 2 --
1 file changed, 2 deletions(-)
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -645,8 +645,6 @@ static int tcmu_check_expired_cmd(int id
target_complete_cmd(cmd->se_cmd, SAM_STAT_CHECK_CONDITION);
cmd->se_cmd = NULL;
- kmem_cache_free(tcmu_cmd_cache, cmd);
-
return 0;
}
Patches currently in stable-queue which might be from agrover@xxxxxxxxxx are
queue-4.4/target-user-fix-use-after-free-of-tcmu_cmds-if-they-are-expired.patch
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