From 7ea6600148c265b1fd53e521022b1d7aec81d974 Mon Sep 17 00:00:00 2001 From: "Serge E. Hallyn" Date: Tue, 29 Dec 2009 14:50:19 -0600 Subject: [PATCH] generic_permission: MAY_OPEN is not write access 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 Signed-off-by: Serge E. Hallyn Tested-by: Mike Kazantsev Signed-off-by: Linus Torvalds --- fs/namei.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/namei.c b/fs/namei.c index 68921d9b5302..b55440baf7ab 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -232,6 +232,7 @@ int generic_permission(struct inode *inode, int mask, /* * 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; -- 2.20.1