From: Christian Lamparter Date: Wed, 21 Sep 2016 16:49:36 +0000 (+0200) Subject: carl9170: fix debugfs crashes X-Git-Tag: v4.9-rc1~148^2~6 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6ee6d1cb391ca85b419f8d18bdfb1f020a5e859c;p=platform%2Fkernel%2Flinux-exynos.git carl9170: fix debugfs crashes Ben Greear reported: > I see lots of instability as soon as I load up the carl9710 NIC. > My application is going to be poking at it's debugfs files... > > BUG: KASAN: slab-out-of-bounds in carl9170_debugfs_read+0xd5/0x2a0 > [carl9170] at addr 0xffff8801bc1208b0 > Read of size 8 by task btserver/5888 > ======================================================================= > BUG kmalloc-256 (Tainted: G W ): kasan: bad access detected > ----------------------------------------------------------------------- > > INFO: Allocated in seq_open+0x50/0x100 age=2690 cpu=2 pid=772 >... This breakage was caused by the introduction of intermediate fops in debugfs by commit 9fd4dcece43a ("debugfs: prevent access to possibly dead file_operations at file open") Thankfully, the original/real fops are still available in d_fsdata. Reported-by: Ben Greear Signed-off-by: Christian Lamparter Cc: stable # 4.7+ Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/net/wireless/ath/carl9170/debug.c b/drivers/net/wireless/ath/carl9170/debug.c index 6808db4..ec3a64e 100644 --- a/drivers/net/wireless/ath/carl9170/debug.c +++ b/drivers/net/wireless/ath/carl9170/debug.c @@ -75,7 +75,8 @@ static ssize_t carl9170_debugfs_read(struct file *file, char __user *userbuf, if (!ar) return -ENODEV; - dfops = container_of(file->f_op, struct carl9170_debugfs_fops, fops); + dfops = container_of(debugfs_real_fops(file), + struct carl9170_debugfs_fops, fops); if (!dfops->read) return -ENOSYS; @@ -127,7 +128,8 @@ static ssize_t carl9170_debugfs_write(struct file *file, if (!ar) return -ENODEV; - dfops = container_of(file->f_op, struct carl9170_debugfs_fops, fops); + dfops = container_of(debugfs_real_fops(file), + struct carl9170_debugfs_fops, fops); if (!dfops->write) return -ENOSYS;