Re: [PATCH 7/8] ima: remove usage of filename parameter

From: Mimi Zohar
Date: Wed Sep 03 2014 - 09:16:53 EST


On Wed, 2014-09-03 at 10:20 +0300, Dmitry Kasatkin wrote:
> In all cases except ima_bprm_check() filename was not defined and
> ima_d_path() was used to find full path.
>
> ima_bprm_check() used to select between bprm->interp and bprm->filename.
> Following dump demonstrates differences between using filename and interp.
>
> bprm->filename
> filename: ./foo.sh, pathname: /root/bin/foo.sh
> filename: ./foo.sh, pathname: /bin/dash
>
> bprm->interp
> filename: ./foo.sh, pathname: /root/bin/foo.sh
> filename: /bin/sh, pathname: /bin/dash
>
> In both cases pathnames are the same.
> This patch removes usage of filename and interp in favor of d_path.
>
> Signed-off-by: Dmitry Kasatkin <d.kasatkin@xxxxxxxxxxx>

Thanks, this has been on my list to do. My only concern is whether we
should be using d_path() or one of the other variants (eg.
dentry_path(), d_absolute_path()). For namespaces, we would want to be
able to differentiate the files.

Please include in this patch description why d_path(), if it is the
case, the best option.

thanks,

Mimi

> ---
> security/integrity/ima/ima_main.c | 19 ++++++++-----------
> 1 file changed, 8 insertions(+), 11 deletions(-)
>
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index aaf5552..673a37e 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -156,8 +156,8 @@ void ima_file_free(struct file *file)
> ima_check_last_writer(iint, inode, file);
> }
>
> -static int process_measurement(struct file *file, const char *filename,
> - int mask, int function, int opened)
> +static int process_measurement(struct file *file, int mask, int function,
> + int opened)
> {
> struct inode *inode = file_inode(file);
> struct integrity_iint_cache *iint;
> @@ -218,7 +218,7 @@ static int process_measurement(struct file *file, const char *filename,
> goto out_digsig;
> }
>
> - pathname = filename ?: ima_d_path(&file->f_path, &pathbuf);
> + pathname = ima_d_path(&file->f_path, &pathbuf);
>
> if (action & IMA_MEASURE)
> ima_store_measurement(iint, file, pathname,
> @@ -254,7 +254,7 @@ out:
> int ima_file_mmap(struct file *file, unsigned long prot)
> {
> if (file && (prot & PROT_EXEC))
> - return process_measurement(file, NULL, MAY_EXEC, MMAP_CHECK, 0);
> + return process_measurement(file, MAY_EXEC, MMAP_CHECK, 0);
> return 0;
> }
>
> @@ -273,10 +273,7 @@ int ima_file_mmap(struct file *file, unsigned long prot)
> */
> int ima_bprm_check(struct linux_binprm *bprm)
> {
> - return process_measurement(bprm->file,
> - (strcmp(bprm->filename, bprm->interp) == 0) ?
> - bprm->filename : bprm->interp,
> - MAY_EXEC, BPRM_CHECK, 0);
> + return process_measurement(bprm->file, MAY_EXEC, BPRM_CHECK, 0);
> }
>
> /**
> @@ -292,7 +289,7 @@ int ima_bprm_check(struct linux_binprm *bprm)
> int ima_file_check(struct file *file, int mask, int opened)
> {
> ima_rdwr_violation_check(file);
> - return process_measurement(file, NULL,
> + return process_measurement(file,
> mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
> FILE_CHECK, opened);
> }
> @@ -317,7 +314,7 @@ int ima_module_check(struct file *file)
> #endif
> return 0; /* We rely on module signature checking */
> }
> - return process_measurement(file, NULL, MAY_EXEC, MODULE_CHECK, 0);
> + return process_measurement(file, MAY_EXEC, MODULE_CHECK, 0);
> }
>
> int ima_fw_from_file(struct file *file, char *buf, size_t size)
> @@ -328,7 +325,7 @@ int ima_fw_from_file(struct file *file, char *buf, size_t size)
> return -EACCES; /* INTEGRITY_UNKNOWN */
> return 0;
> }
> - return process_measurement(file, NULL, MAY_EXEC, FIRMWARE_CHECK, 0);
> + return process_measurement(file, MAY_EXEC, FIRMWARE_CHECK, 0);
> }
>
> static int __init init_ima(void)


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