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| author | Darrick J. Wong <darrick.wong@oracle.com> | 2018-10-30 10:41:41 +1100 |
|---|---|---|
| committer | Dave Chinner <david@fromorbit.com> | 2018-10-30 10:41:41 +1100 |
| commit | 8dde90bca6fca3736ea20109654bcf6dcf2ecf1d (patch) | |
| tree | 4ead8c271da07d766432bb0847026f73054842cd /fs/read_write.c | |
| parent | 3d28193e1df043764deb7abdaba5e3a6660bc393 (diff) | |
| download | lwn-8dde90bca6fca3736ea20109654bcf6dcf2ecf1d.tar.gz lwn-8dde90bca6fca3736ea20109654bcf6dcf2ecf1d.zip | |
vfs: remap helper should update destination inode metadata
Extend generic_remap_file_range_prep to handle inode metadata updates
when remapping into a file. If the operation can possibly alter the
file contents, we must update the ctime and mtime and remove security
privileges, just like we do for regular file writes.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/read_write.c')
| -rw-r--r-- | fs/read_write.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index ebcbfc4f2907..b61bd3fc7154 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1820,6 +1820,25 @@ int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, if (ret) return ret; + /* If can't alter the file contents, we're done. */ + if (!(remap_flags & REMAP_FILE_DEDUP)) { + /* Update the timestamps, since we can alter file contents. */ + if (!(file_out->f_mode & FMODE_NOCMTIME)) { + ret = file_update_time(file_out); + if (ret) + return ret; + } + + /* + * Clear the security bits if the process is not being run by + * root. This keeps people from modifying setuid and setgid + * binaries. + */ + ret = file_remove_privs(file_out); + if (ret) + return ret; + } + return 1; } EXPORT_SYMBOL(generic_remap_file_range_prep); |