aboutsummaryrefslogtreecommitdiffstats
path: root/mm/memory.c
diff options
context:
space:
mode:
authorDarrick J. Wong <darrick.wong@oracle.com>2019-08-20 07:55:16 -0700
committerDarrick J. Wong <darrick.wong@oracle.com>2019-08-20 07:55:16 -0700
commitdc617f29dbe5ef0c8ced65ce62c464af1daaab3d (patch)
tree3596eb0d334f04f87088c735748bba8e66a71cad /mm/memory.c
parentmm: set S_SWAPFILE on blockdev swap devices (diff)
downloadlinux-dev-dc617f29dbe5ef0c8ced65ce62c464af1daaab3d.tar.xz
linux-dev-dc617f29dbe5ef0c8ced65ce62c464af1daaab3d.zip
vfs: don't allow writes to swap files
Don't let userspace write to an active swap file because the kernel effectively has a long term lease on the storage and things could get seriously corrupted if we let this happen. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to '')
-rw-r--r--mm/memory.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c
index e2bb51b6242e..b1dff75640b7 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2196,6 +2196,10 @@ static vm_fault_t do_page_mkwrite(struct vm_fault *vmf)
vmf->flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE;
+ if (vmf->vma->vm_file &&
+ IS_SWAPFILE(vmf->vma->vm_file->f_mapping->host))
+ return VM_FAULT_SIGBUS;
+
ret = vmf->vma->vm_ops->page_mkwrite(vmf);
/* Restore original flags so that caller is not surprised */
vmf->flags = old_flags;