diff mbox series

[5.12,309/677] m68k: Add missing mmap_read_lock() to sys_cacheflush()

Message ID 20210512144847.479764980@linuxfoundation.org
State Superseded
Headers show
Series None | expand

Commit Message

Greg KH May 12, 2021, 2:45 p.m. UTC 
From: Liam Howlett <liam.howlett@oracle.com>

[ 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: cd2567b6850b1648 ("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>
---
 arch/m68k/kernel/sys_m68k.c | 2 ++
 1 file changed, 2 insertions(+)
diff mbox series

Patch

diff --git a/arch/m68k/kernel/sys_m68k.c b/arch/m68k/kernel/sys_m68k.c
index 1c235d8f53f3..f55bdcb8e4f1 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;