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 <[email protected]>
Signed-off-by: Serge E. Hallyn <[email protected]>
Tested-by: Mike Kazantsev <[email protected]>
---
fs/namei.c | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 68921d9..b55440b 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;
--
1.6.0.4