| From | Greg Kroah-Hartman <> | Subject | [PATCH 100/101] generic_permission: MAY_OPEN is not write access | Date | Tue, 5 Jan 2010 11:21:28 -0800 |
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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 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c index d11f404..a2b3c28 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -234,6 +234,7 @@ 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; -- 1.6.6
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