aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorSasha Levin <levinsasha928@gmail.com>2012-07-17 00:01:26 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-10-28 10:14:13 -0700
commitbaecc6ef799c7ab9a5fc0ba29ee560a5c264f306 (patch)
treeea9f341b7b0f2907d574dde7a8a588b2b7e1633e
parent1b91a891bc337ecec08dea5436be0bbb03fec12b (diff)
SUNRPC: Prevent kernel stack corruption on long values of flush
commit 212ba90696ab4884e2025b0b13726d67aadc2cd4 upstream. The buffer size in read_flush() is too small for the longest possible values for it. This can lead to a kernel stack corruption: [ 43.047329] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff833e64b4 [ 43.047329] [ 43.049030] Pid: 6015, comm: trinity-child18 Tainted: G W 3.5.0-rc7-next-20120716-sasha #221 [ 43.050038] Call Trace: [ 43.050435] [<ffffffff836c60c2>] panic+0xcd/0x1f4 [ 43.050931] [<ffffffff833e64b4>] ? read_flush.isra.7+0xe4/0x100 [ 43.051602] [<ffffffff810e94e6>] __stack_chk_fail+0x16/0x20 [ 43.052206] [<ffffffff833e64b4>] read_flush.isra.7+0xe4/0x100 [ 43.052951] [<ffffffff833e6500>] ? read_flush_pipefs+0x30/0x30 [ 43.053594] [<ffffffff833e652c>] read_flush_procfs+0x2c/0x30 [ 43.053596] [<ffffffff812b9a8c>] proc_reg_read+0x9c/0xd0 [ 43.053596] [<ffffffff812b99f0>] ? proc_reg_write+0xd0/0xd0 [ 43.053596] [<ffffffff81250d5b>] do_loop_readv_writev+0x4b/0x90 [ 43.053596] [<ffffffff81250fd6>] do_readv_writev+0xf6/0x1d0 [ 43.053596] [<ffffffff812510ee>] vfs_readv+0x3e/0x60 [ 43.053596] [<ffffffff812511b8>] sys_readv+0x48/0xb0 [ 43.053596] [<ffffffff8378167d>] system_call_fastpath+0x1a/0x1f Signed-off-by: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/sunrpc/cache.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index de0b0f39d9d..76cb304f3f1 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -1406,11 +1406,11 @@ static ssize_t read_flush(struct file *file, char __user *buf,
size_t count, loff_t *ppos,
struct cache_detail *cd)
{
- char tbuf[20];
+ char tbuf[22];
unsigned long p = *ppos;
size_t len;
- sprintf(tbuf, "%lu\n", convert_to_wallclock(cd->flush_time));
+ snprintf(tbuf, sizeof(tbuf), "%lu\n", convert_to_wallclock(cd->flush_time));
len = strlen(tbuf);
if (p >= len)
return 0;