path: root/kernel
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authorVegard Nossum <vegard.nossum@oracle.com>2014-02-16 22:24:17 +0100
committerThomas Gleixner <tglx@linutronix.de>2014-02-21 21:27:10 +0100
commit4efbc454ba68def5ef285b26ebfcfdb605b52755 (patch)
tree96fd992414451a19797a38476afed61b352d3d4f /kernel
parent3cf1962cdbf6b3a9e3ef21116d215bbab350ea37 (diff)
sched: Fix information leak in sys_sched_getattr()
We're copying the on-stack structure to userspace, but forgot to give the right number of bytes to copy. This allows the calling process to obtain up to PAGE_SIZE bytes from the stack (and possibly adjacent kernel memory). This fix copies only as much as we actually have on the stack (attr->size defaults to the size of the struct) and leaves the rest of the userspace-provided buffer untouched. Found using kmemcheck + trinity. Fixes: d50dde5a10f30 ("sched: Add new scheduler syscalls to support an extended scheduling parameters ABI") Cc: Dario Faggioli <raistlin@linux.it> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1392585857-10725-1-git-send-email-vegard.nossum@oracle.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel')
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 33d030a133d..a6e7470166c 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3786,7 +3786,7 @@ static int sched_read_attr(struct sched_attr __user *uattr,
attr->size = usize;
- ret = copy_to_user(uattr, attr, usize);
+ ret = copy_to_user(uattr, attr, attr->size);
if (ret)
return -EFAULT;