* [PATCH] psi: Fix OOB write when writing 0 bytes to psi files
@ 2020-02-03 21:22 Suren Baghdasaryan
2020-02-04 18:55 ` Johannes Weiner
2020-02-11 12:47 ` [tip: sched/urgent] sched/psi: Fix OOB write when writing 0 bytes to PSI files tip-bot2 for Suren Baghdasaryan
0 siblings, 2 replies; 4+ messages in thread
From: Suren Baghdasaryan @ 2020-02-03 21:22 UTC (permalink / raw)
To: surenb
Cc: mingo, peterz, hannes, juri.lelli, vincent.guittot,
dietmar.eggemann, rostedt, bsegall, mgorman, linux-kernel,
kernel-team
Issuing write() with count parameter set to 0 on any file under
/proc/pressure/ will cause an OOB write because of the access to
buf[buf_size-1] when NUL-termination is performed. Fix this by checking
for buf_size to be non-zero.
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
---
kernel/sched/psi.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index db7b50bba3f1..38ccd49b9bf6 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -1199,6 +1199,9 @@ static ssize_t psi_write(struct file *file, const char __user *user_buf,
if (static_branch_likely(&psi_disabled))
return -EOPNOTSUPP;
+ if (!nbytes)
+ return -EINVAL;
+
buf_size = min(nbytes, sizeof(buf));
if (copy_from_user(buf, user_buf, buf_size))
return -EFAULT;
--
2.25.0.341.g760bfbb309-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] psi: Fix OOB write when writing 0 bytes to psi files
2020-02-03 21:22 [PATCH] psi: Fix OOB write when writing 0 bytes to psi files Suren Baghdasaryan
@ 2020-02-04 18:55 ` Johannes Weiner
2020-02-06 14:03 ` Peter Zijlstra
2020-02-11 12:47 ` [tip: sched/urgent] sched/psi: Fix OOB write when writing 0 bytes to PSI files tip-bot2 for Suren Baghdasaryan
1 sibling, 1 reply; 4+ messages in thread
From: Johannes Weiner @ 2020-02-04 18:55 UTC (permalink / raw)
To: Suren Baghdasaryan
Cc: mingo, peterz, juri.lelli, vincent.guittot, dietmar.eggemann,
rostedt, bsegall, mgorman, linux-kernel, kernel-team
On Mon, Feb 03, 2020 at 01:22:16PM -0800, Suren Baghdasaryan wrote:
> Issuing write() with count parameter set to 0 on any file under
> /proc/pressure/ will cause an OOB write because of the access to
> buf[buf_size-1] when NUL-termination is performed. Fix this by checking
> for buf_size to be non-zero.
>
> Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Thanks Suren.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] psi: Fix OOB write when writing 0 bytes to psi files
2020-02-04 18:55 ` Johannes Weiner
@ 2020-02-06 14:03 ` Peter Zijlstra
0 siblings, 0 replies; 4+ messages in thread
From: Peter Zijlstra @ 2020-02-06 14:03 UTC (permalink / raw)
To: Johannes Weiner
Cc: Suren Baghdasaryan, mingo, juri.lelli, vincent.guittot,
dietmar.eggemann, rostedt, bsegall, mgorman, linux-kernel,
kernel-team
On Tue, Feb 04, 2020 at 01:55:23PM -0500, Johannes Weiner wrote:
> On Mon, Feb 03, 2020 at 01:22:16PM -0800, Suren Baghdasaryan wrote:
> > Issuing write() with count parameter set to 0 on any file under
> > /proc/pressure/ will cause an OOB write because of the access to
> > buf[buf_size-1] when NUL-termination is performed. Fix this by checking
> > for buf_size to be non-zero.
> >
> > Signed-off-by: Suren Baghdasaryan <surenb@google.com>
>
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Thanks!
^ permalink raw reply [flat|nested] 4+ messages in thread
* [tip: sched/urgent] sched/psi: Fix OOB write when writing 0 bytes to PSI files
2020-02-03 21:22 [PATCH] psi: Fix OOB write when writing 0 bytes to psi files Suren Baghdasaryan
2020-02-04 18:55 ` Johannes Weiner
@ 2020-02-11 12:47 ` tip-bot2 for Suren Baghdasaryan
1 sibling, 0 replies; 4+ messages in thread
From: tip-bot2 for Suren Baghdasaryan @ 2020-02-11 12:47 UTC (permalink / raw)
To: linux-tip-commits
Cc: Suren Baghdasaryan, Peter Zijlstra (Intel),
Ingo Molnar, Johannes Weiner, x86, LKML
The following commit has been merged into the sched/urgent branch of tip:
Commit-ID: 6fcca0fa48118e6d63733eb4644c6cd880c15b8f
Gitweb: https://git.kernel.org/tip/6fcca0fa48118e6d63733eb4644c6cd880c15b8f
Author: Suren Baghdasaryan <surenb@google.com>
AuthorDate: Mon, 03 Feb 2020 13:22:16 -08:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Tue, 11 Feb 2020 13:00:02 +01:00
sched/psi: Fix OOB write when writing 0 bytes to PSI files
Issuing write() with count parameter set to 0 on any file under
/proc/pressure/ will cause an OOB write because of the access to
buf[buf_size-1] when NUL-termination is performed. Fix this by checking
for buf_size to be non-zero.
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Link: https://lkml.kernel.org/r/20200203212216.7076-1-surenb@google.com
---
kernel/sched/psi.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index db7b50b..38ccd49 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -1199,6 +1199,9 @@ static ssize_t psi_write(struct file *file, const char __user *user_buf,
if (static_branch_likely(&psi_disabled))
return -EOPNOTSUPP;
+ if (!nbytes)
+ return -EINVAL;
+
buf_size = min(nbytes, sizeof(buf));
if (copy_from_user(buf, user_buf, buf_size))
return -EFAULT;
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-02-11 12:48 UTC | newest]
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2020-02-03 21:22 [PATCH] psi: Fix OOB write when writing 0 bytes to psi files Suren Baghdasaryan
2020-02-04 18:55 ` Johannes Weiner
2020-02-06 14:03 ` Peter Zijlstra
2020-02-11 12:47 ` [tip: sched/urgent] sched/psi: Fix OOB write when writing 0 bytes to PSI files tip-bot2 for Suren Baghdasaryan
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