From f829b4b212a315b912cb23fd10aaf30534bb5ce9 Mon Sep 17 00:00:00 2001 From: Liam Howlett Date: Wed, 7 Apr 2021 20:00:45 +0000 Subject: [PATCH] m68k: Add missing mmap_read_lock() to sys_cacheflush() 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: cd2567b6850b1648 ("m68k: call find_vma with the mmap_sem held in sys_cacheflush()") Signed-off-by: Liam R. Howlett Reviewed-by: Matthew Wilcox (Oracle) Link: https://lore.kernel.org/r/20210407200032.764445-1-Liam.Howlett@Oracle.com Signed-off-by: Geert Uytterhoeven --- arch/m68k/kernel/sys_m68k.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/m68k/kernel/sys_m68k.c b/arch/m68k/kernel/sys_m68k.c index 1c235d8..f55bdcb 100644 --- a/arch/m68k/kernel/sys_m68k.c +++ b/arch/m68k/kernel/sys_m68k.c @@ -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; -- 2.7.4