Swapoff used old_block_size from swap_info which could be overwritten by
concurrent swapon.
Reported-by: Weijie Yang <weijie.yang.kh@xxxxxxxxx>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx>
---
mm/swapfile.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 3963fc2..de7c904 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1824,6 +1824,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
struct filename *pathname;
int i, type, prev;
int err;
+ unsigned int old_block_size;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
@@ -1914,6 +1915,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
}
swap_file = p->swap_file;
+ old_block_size = p->old_block_size;
p->swap_file = NULL;
p->max = 0;
swap_map = p->swap_map;
@@ -1938,7 +1940,7 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
inode = mapping->host;
if (S_ISBLK(inode->i_mode)) {
struct block_device *bdev = I_BDEV(inode);
- set_blocksize(bdev, p->old_block_size);
+ set_blocksize(bdev, old_block_size);
blkdev_put(bdev, FMODE_READ | FMODE_WRITE | FMODE_EXCL);
} else {
mutex_lock(&inode->i_mutex);
--
1.7.9.5
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