[PATCH 1/1] eCryptfs: Remove mmap from directory operations

[Herton Ronaldo Krzesinski]

On Wed, Feb 15, 2012 at 05:24:29PM +0000, Colin King wrote:
> From: Colin Ian King <colin.king at canonical.com>
> 
> 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 at sysphere.org>
> Signed-off-by: Tyler Hicks <tyhicks at linux.vnet.ibm.com>

Ack, just missing the backported from
38e3eaeedcac75360af8a92e7b66956ec4f334e5 line here.

> Signed-off-by: Colin Ian King <colin.king at canonical.com>
> ---
>  fs/ecryptfs/file.c |    1 -
>  1 files changed, 0 insertions(+), 1 deletions(-)
> 
> diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
> index 4e25328..d8adc51 100644
> --- a/fs/ecryptfs/file.c
> +++ b/fs/ecryptfs/file.c
> @@ -327,7 +327,6 @@ const struct file_operations ecryptfs_dir_fops = {
>  #ifdef CONFIG_COMPAT
>  	.compat_ioctl = ecryptfs_compat_ioctl,
>  #endif
> -	.mmap = generic_file_mmap,
>  	.open = ecryptfs_open,
>  	.flush = ecryptfs_flush,
>  	.release = ecryptfs_release,
> -- 
> 1.7.0.4
> 

-- 
[]'s
Herton