| From c03d613d66b47a71a6e7851308f8a3ad008a0a71 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Wed, 7 Apr 2021 20:00:45 +0000 |
| Subject: m68k: Add missing mmap_read_lock() to sys_cacheflush() |
| |
| 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 --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; |
| |
| -- |
| 2.30.2 |
| |
