Messages in this thread Patch in this message | | | From | Chao Yu <> | Subject | [PATCH] f2fs: fix fallocate to use file_modified to update permissions consistently | Date | Tue, 17 May 2022 11:37:23 +0800 |
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This patch tries to fix permission consistency issue as all other mainline filesystems.
Since the initial introduction of (posix) fallocate back at the turn of the century, it has been possible to use this syscall to change the user-visible contents of files. This can happen by extending the file size during a preallocation, or through any of the newer modes (punch, zero, collapse, insert range). Because the call can be used to change file contents, we should treat it like we do any other modification to a file -- update the mtime, and drop set[ug]id privileges/capabilities.
The VFS function file_modified() does all this for us if pass it a locked inode, so let's make fallocate drop permissions correctly.
Cc: stable@kernel.org Signed-off-by: Chao Yu <chao.yu@oppo.com> --- fs/f2fs/file.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 73ba1c6dceaa..f23a7cdee657 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1783,6 +1783,10 @@ static long f2fs_fallocate(struct file *file, int mode, inode_lock(inode); + ret = file_modified(file); + if (ret) + goto out; + if (mode & FALLOC_FL_PUNCH_HOLE) { if (offset >= inode->i_size) goto out; -- 2.25.1
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