Messages in this thread Patch in this message | | | Date | Tue, 05 Jan 2010 12:02:27 -0800 | From | Greg KH <> | Subject | [31/39] generic_permission: MAY_OPEN is not write access |
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2.6.31-stable review patch. If anyone has any objections, please let us know.
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From: Serge E. Hallyn <serue@us.ibm.com>
commit 7ea6600148c265b1fd53e521022b1d7aec81d974 upstream.
generic_permission was refusing CAP_DAC_READ_SEARCH-enabled processes from opening DAC-protected files read-only, because do_filp_open adds MAY_OPEN to the open mask.
Ignore MAY_OPEN. After this patch, CAP_DAC_READ_SEARCH is again sufficient to open(fname, O_RDONLY) on a file to which DAC otherwise refuses us read permission.
Reported-by: Mike Kazantsev <mk.fraggod@gmail.com> Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Tested-by: Mike Kazantsev <mk.fraggod@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- fs/namei.c | 1 + 1 file changed, 1 insertion(+)
--- a/fs/namei.c +++ b/fs/namei.c @@ -221,6 +221,7 @@ int generic_permission(struct inode *ino /* * Searching includes executable on directories, else just read. */ + mask &= MAY_READ | MAY_WRITE | MAY_EXEC; if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE))) if (capable(CAP_DAC_READ_SEARCH)) return 0;
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