On Thu, 2018-02-15 at 16:16 +0100, Greg Kroah-Hartman wrote:
4.4-stable review patch. If anyone has any objections, please let me know.
From: Al Viro viro@zeniv.linux.org.uk
commit 21fc61c73c3903c4c312d0802da01ec2b323d174 upstream.
kmap() in page_follow_link_light() needed to go - allowing to hold an arbitrary number of kmaps for long is a great way to deadlocking the system.
new helper (inode_nohighmem(inode)) needs to be used for pagecache symlinks inodes; done for all in-tree cases. page_follow_link_light() instrumented to yell about anything missed.
Except that this backport only updates ext4 and f2fs (and doesn't add the warning). I suppose that's all matters for Android, but it would be nice to get a more complete backport into 4.4-stable...
Ben.
Signed-off-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Jin Qian jinqian@google.com Signed-off-by: Jin Qian jinqian@android.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
[...]