mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
synced 2025-01-09 15:29:16 +00:00
c42dd069be
When configfs_lookup() is executing list_for_each_entry(),
it is possible that configfs_dir_lseek() is calling list_del().
Some unfortunate interleavings of them can cause a kernel NULL
pointer dereference error
Thread 1 Thread 2
//configfs_dir_lseek() //configfs_lookup()
list_del(&cursor->s_sibling);
list_for_each_entry(sd, ...)
Fix this by grabbing configfs_dirent_lock in configfs_lookup()
while iterating ->s_children.
Signed-off-by: Sishuai Gong <sishuai@purdue.edu>
Signed-off-by: Christoph Hellwig <hch@lst.de>