m68k: Add missing mmap_read_lock() to sys_cacheflush()

[ Upstream commit f829b4b212a315b912cb23fd10aaf30534bb5ce9 ]

When the superuser flushes the entire cache, the mmap_read_lock() is not
taken, but mmap_read_unlock() is called.  Add the missing
mmap_read_lock() call.

Fixes: cd2567b685 ("m68k: call find_vma with the mmap_sem held in sys_cacheflush()")
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20210407200032.764445-1-Liam.Howlett@Oracle.com
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Liam Howlett 2021-04-07 20:00:45 +00:00 committed by Greg Kroah-Hartman
parent 99d2fa2daf
commit 58ee5a0de1

View File

@ -388,6 +388,8 @@ sys_cacheflush (unsigned long addr, int scope, int cache, unsigned long len)
ret = -EPERM;
if (!capable(CAP_SYS_ADMIN))
goto out;
mmap_read_lock(current->mm);
} else {
struct vm_area_struct *vma;