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

[Tim Gardner]

On 02/15/2012 10:24 AM, 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>
> 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,

I'll add 'backported from 38e3eaeedcac75360af8a92e7b66956ec4f334e5' and 
send it to stable.

rtg
-- 
Tim Gardner tim.gardner at canonical.com