2016-12-12 08:35:53

by Seung-Woo Kim

Subject: [PATCH] Smack: ignore private inode for file functions

The access to fd from anon_inode is always failed because there is
no set xattr operations. So this patch fixes to ignore private
inode including anon_inode for file functions.

It was only ignored for smack_file_receive() to share dma-buf fd,
but dma-buf has other functions like ioctl and mmap.

Reference: https://lkml.org/lkml/2015/4/17/16

Signed-off-by: Seung-Woo Kim <[email protected]>
---
security/smack/smack_lsm.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 1cb0602..e7f0bbe 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1632,6 +1632,9 @@ static int smack_file_ioctl(struct file *file, unsigned int cmd,
struct smk_audit_info ad;
struct inode *inode = file_inode(file);

+ if (unlikely(IS_PRIVATE(inode)))
+ return 0;
+
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);

@@ -1661,6 +1664,9 @@ static int smack_file_lock(struct file *file, unsigned int cmd)
int rc;
struct inode *inode = file_inode(file);

+ if (unlikely(IS_PRIVATE(inode)))
+ return 0;
+
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
smk_ad_setfield_u_fs_path(&ad, file->f_path);
rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
@@ -1687,6 +1693,9 @@ static int smack_file_fcntl(struct file *file, unsigned int cmd,
int rc = 0;
struct inode *inode = file_inode(file);

+ if (unlikely(IS_PRIVATE(inode)))
+ return 0;
+
switch (cmd) {
case F_GETLK:
break;
@@ -1740,6 +1749,9 @@ static int smack_mmap_file(struct file *file,
if (file == NULL)
return 0;

+ if (unlikely(IS_PRIVATE(file_inode(file))))
+ return 0;
+
isp = file_inode(file)->i_security;
if (isp->smk_mmap == NULL)
return 0;
--
1.7.9.5

2016-12-15 23:59:21

by Casey Schaufler

Subject: Re: [PATCH] Smack: ignore private inode for file functions

On 12/12/2016 12:35 AM, Seung-Woo Kim wrote:
> The access to fd from anon_inode is always failed because there is
> no set xattr operations. So this patch fixes to ignore private
> inode including anon_inode for file functions.
>
> It was only ignored for smack_file_receive() to share dma-buf fd,
> but dma-buf has other functions like ioctl and mmap.
>
> Reference: https://lkml.org/lkml/2015/4/17/16
>
> Signed-off-by: Seung-Woo Kim <[email protected]>

Acked-by: Casey Schaufler <[email protected]>

I have queued this for my 4.11 tree.

> ---
> security/smack/smack_lsm.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 1cb0602..e7f0bbe 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -1632,6 +1632,9 @@ static int smack_file_ioctl(struct file *file, unsigned int cmd,
> struct smk_audit_info ad;
> struct inode *inode = file_inode(file);
>
> + if (unlikely(IS_PRIVATE(inode)))
> + return 0;
> +
> smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
> smk_ad_setfield_u_fs_path(&ad, file->f_path);
>
> @@ -1661,6 +1664,9 @@ static int smack_file_lock(struct file *file, unsigned int cmd)
> int rc;
> struct inode *inode = file_inode(file);
>
> + if (unlikely(IS_PRIVATE(inode)))
> + return 0;
> +
> smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
> smk_ad_setfield_u_fs_path(&ad, file->f_path);
> rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
> @@ -1687,6 +1693,9 @@ static int smack_file_fcntl(struct file *file, unsigned int cmd,
> int rc = 0;
> struct inode *inode = file_inode(file);
>
> + if (unlikely(IS_PRIVATE(inode)))
> + return 0;
> +
> switch (cmd) {
> case F_GETLK:
> break;
> @@ -1740,6 +1749,9 @@ static int smack_mmap_file(struct file *file,
> if (file == NULL)
> return 0;
>
> + if (unlikely(IS_PRIVATE(file_inode(file))))
> + return 0;
> +
> isp = file_inode(file)->i_security;
> if (isp->smk_mmap == NULL)
> return 0;