diff options
| author | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2011-04-13 10:31:52 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-04-22 08:44:17 -0700 |
| commit | 4f4f117c9b75a3df8bfd552f1c4020a9206fdca5 (patch) | |
| tree | b1dce568247da6cf9f6b33f80cca57acb5a466d7 | |
| parent | 286ef426e335e89a43e63ee5b8ad129b651f9793 (diff) | |
UBIFS: fix oops when R/O file-system is fsync'ed
commit 78530bf7f2559b317c04991b52217c1608d5a58d upstream.
This patch fixes severe UBIFS bug: UBIFS oopses when we 'fsync()' an
file on R/O-mounter file-system. We (the UBIFS authors) incorrectly
thought that VFS would not propagate 'fsync()' down to the file-system
if it is read-only, but this is not the case.
It is easy to exploit this bug using the following simple perl script:
use strict;
use File::Sync qw(fsync sync);
die "File path is not specified" if not defined $ARGV[0];
my $path = $ARGV[0];
open FILE, "<", "$path" or die "Cannot open $path: $!";
fsync(\*FILE) or die "cannot fsync $path: $!";
close FILE or die "Cannot close $path: $!";
Thanks to Reuben Dowle <Reuben.Dowle@navico.com> for reporting about this
issue.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reported-by: Reuben Dowle <Reuben.Dowle@navico.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | fs/ubifs/file.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c index 1009adc8d602..e90dd7ee2d3a 100644 --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -1311,6 +1311,9 @@ int ubifs_fsync(struct file *file, struct dentry *dentry, int datasync) dbg_gen("syncing inode %lu", inode->i_ino); + if (inode->i_sb->s_flags & MS_RDONLY) + return 0; + /* * VFS has already synchronized dirty pages for this inode. Synchronize * the inode unless this is a 'datasync()' call. |