Messages in this thread Patch in this message | | | Date | Tue, 11 Feb 2020 12:47:47 -0000 | From | "tip-bot2 for Suren Baghdasaryan" <> | Subject | [tip: sched/urgent] sched/psi: Fix OOB write when writing 0 bytes to PSI files |
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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;
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