| Message ID | 20190529174318.22424-8-amir73il@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fixes for major copy_file_range() issues | expand |
On Wed, May 29, 2019 at 08:43:11PM +0300, Amir Goldstein wrote: > Note that by using the helper, the order of calling file_remove_privs() > after file_update_mtime() in xfs_file_aio_write_checks() has changed. > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> > --- > fs/xfs/xfs_file.c | 15 +-------------- > 1 file changed, 1 insertion(+), 14 deletions(-) > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index 76748255f843..916a35cae5e9 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -367,20 +367,7 @@ xfs_file_aio_write_checks( > * lock above. Eventually we should look into a way to avoid > * the pointless lock roundtrip. > */ > - if (likely(!(file->f_mode & FMODE_NOCMTIME))) { ...especially since here we think NOCMTIME is likely /not/ to be set. > - error = file_update_time(file); > - if (error) > - return error; > - } > - > - /* > - * If we're writing the file then make sure to clear the setuid and > - * setgid bits if the process is not being run by root. This keeps > - * people from modifying setuid and setgid binaries. > - */ > - if (!IS_NOSEC(inode)) > - return file_remove_privs(file); Hm, file_modified doesn't have the !IS_NOSEC check guarding file_remove_privs, are you sure it's ok to remove the suid bits unconditionally? Even if SB_NOSEC (and therefore S_NOSEC) are set? --D > - return 0; > + return file_modified(file); > } > > static int > -- > 2.17.1 >
On Wed, May 29, 2019 at 9:31 PM Darrick J. Wong <darrick.wong@oracle.com> wrote: > > On Wed, May 29, 2019 at 08:43:11PM +0300, Amir Goldstein wrote: > > Note that by using the helper, the order of calling file_remove_privs() > > after file_update_mtime() in xfs_file_aio_write_checks() has changed. > > > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> > > --- > > fs/xfs/xfs_file.c | 15 +-------------- > > 1 file changed, 1 insertion(+), 14 deletions(-) > > > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > > index 76748255f843..916a35cae5e9 100644 > > --- a/fs/xfs/xfs_file.c > > +++ b/fs/xfs/xfs_file.c > > @@ -367,20 +367,7 @@ xfs_file_aio_write_checks( > > * lock above. Eventually we should look into a way to avoid > > * the pointless lock roundtrip. > > */ > > - if (likely(!(file->f_mode & FMODE_NOCMTIME))) { > > ...especially since here we think NOCMTIME is likely /not/ to be set. > > > - error = file_update_time(file); > > - if (error) > > - return error; > > - } > > - > > - /* > > - * If we're writing the file then make sure to clear the setuid and > > - * setgid bits if the process is not being run by root. This keeps > > - * people from modifying setuid and setgid binaries. > > - */ > > - if (!IS_NOSEC(inode)) > > - return file_remove_privs(file); > > Hm, file_modified doesn't have the !IS_NOSEC check guarding > file_remove_privs, are you sure it's ok to remove the suid bits > unconditionally? Even if SB_NOSEC (and therefore S_NOSEC) are set? > file_remove_privs() has its own IS_NOSEC() check. Thanks, Amir.
On Wed, May 29, 2019 at 10:10:37PM +0300, Amir Goldstein wrote: > On Wed, May 29, 2019 at 9:31 PM Darrick J. Wong <darrick.wong@oracle.com> wrote: > > > > On Wed, May 29, 2019 at 08:43:11PM +0300, Amir Goldstein wrote: > > > Note that by using the helper, the order of calling file_remove_privs() > > > after file_update_mtime() in xfs_file_aio_write_checks() has changed. > > > > > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> > > > --- > > > fs/xfs/xfs_file.c | 15 +-------------- > > > 1 file changed, 1 insertion(+), 14 deletions(-) > > > > > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > > > index 76748255f843..916a35cae5e9 100644 > > > --- a/fs/xfs/xfs_file.c > > > +++ b/fs/xfs/xfs_file.c > > > @@ -367,20 +367,7 @@ xfs_file_aio_write_checks( > > > * lock above. Eventually we should look into a way to avoid > > > * the pointless lock roundtrip. > > > */ > > > - if (likely(!(file->f_mode & FMODE_NOCMTIME))) { > > > > ...especially since here we think NOCMTIME is likely /not/ to be set. > > > > > - error = file_update_time(file); > > > - if (error) > > > - return error; > > > - } > > > - > > > - /* > > > - * If we're writing the file then make sure to clear the setuid and > > > - * setgid bits if the process is not being run by root. This keeps > > > - * people from modifying setuid and setgid binaries. > > > - */ > > > - if (!IS_NOSEC(inode)) > > > - return file_remove_privs(file); > > > > Hm, file_modified doesn't have the !IS_NOSEC check guarding > > file_remove_privs, are you sure it's ok to remove the suid bits > > unconditionally? Even if SB_NOSEC (and therefore S_NOSEC) are set? > > > > file_remove_privs() has its own IS_NOSEC() check. Ah, ok, Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> --D > Thanks, > Amir.
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 76748255f843..916a35cae5e9 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -367,20 +367,7 @@ xfs_file_aio_write_checks( * lock above. Eventually we should look into a way to avoid * the pointless lock roundtrip. */ - if (likely(!(file->f_mode & FMODE_NOCMTIME))) { - error = file_update_time(file); - if (error) - return error; - } - - /* - * If we're writing the file then make sure to clear the setuid and - * setgid bits if the process is not being run by root. This keeps - * people from modifying setuid and setgid binaries. - */ - if (!IS_NOSEC(inode)) - return file_remove_privs(file); - return 0; + return file_modified(file); } static int
Note that by using the helper, the order of calling file_remove_privs() after file_update_mtime() in xfs_file_aio_write_checks() has changed. Signed-off-by: Amir Goldstein <amir73il@gmail.com> --- fs/xfs/xfs_file.c | 15 +-------------- 1 file changed, 1 insertion(+), 14 deletions(-)