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| author | Darrick J. Wong <darrick.wong@oracle.com> | 2019-08-20 16:55:16 +0200 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2019-08-20 16:55:16 +0200 |
| commit | dc617f29dbe5ef0c8ced65ce62c464af1daaab3d (patch) | |
| tree | 3596eb0d334f04f87088c735748bba8e66a71cad /mm/memory.c | |
| parent | mm: set S_SWAPFILE on blockdev swap devices (diff) | |
| download | linux-dc617f29dbe5ef0c8ced65ce62c464af1daaab3d.tar.xz linux-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 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 4 |
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; |