eCryptfs: Remove mmap from directory operations
commit38e3eaeedcac75360af8a92e7b66956ec4f334e5
authorTyler Hicks <tyhicks@linux.vnet.ibm.com>
Tue, 3 Nov 2009 20:56:06 +0000 (3 14:56 -0600)
committerTyler Hicks <tyhicks@linux.vnet.ibm.com>
Wed, 20 Jan 2010 04:32:11 +0000 (19 22:32 -0600)
treeba194b5451033e29137d4c797edd8d508c470d42
parentf8f484d1b6677dd5cd5e7e605db747e8c30bbd47
eCryptfs: Remove mmap from directory operations

Adrian reported that mkfontscale didn't work inside of eCryptfs mounts.
Strace revealed the following:

open("./", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY|O_CLOEXEC) = 3
fcntl64(3, F_GETFD) = 0x1 (flags FD_CLOEXEC)
open("./fonts.scale", O_WRONLY|O_CREAT|O_TRUNC, 0666) = 4
getdents(3, /* 80 entries */, 32768) = 2304
open("./.", O_RDONLY) = 5
fcntl64(5, F_SETFD, FD_CLOEXEC) = 0
fstat64(5, {st_mode=S_IFDIR|0755, st_size=16384, ...}) = 0
mmap2(NULL, 16384, PROT_READ, MAP_PRIVATE, 5, 0) = 0xb7fcf000
close(5) = 0
--- SIGBUS (Bus error) @ 0 (0) ---
+++ killed by SIGBUS +++

The mmap2() on a directory was successful, resulting in a SIGBUS
signal later.  This patch removes mmap() from the list of possible
ecryptfs_dir_fops so that mmap() isn't possible on eCryptfs directory
files.

https://bugs.launchpad.net/ecryptfs/+bug/400443

Reported-by: Adrian C. <anrxc@sysphere.org>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
fs/ecryptfs/file.c