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Date: Wed, 27 Oct 2021 09:48:41 +0300
From: Amir Goldstein <amir73il@...il.com>
To: Gabriel Krisman Bertazi <krisman@...labora.com>
Cc: LTP List <ltp@...ts.linux.it>, Jan Kara <jack@...e.com>,
Khazhismel Kumykov <khazhy@...gle.com>, kernel@...labora.com,
Ext4 <linux-ext4@...r.kernel.org>,
Matthew Bobrowski <repnop@...gle.com>
Subject: Re: [PATCH v2 05/10] syscalls/fanotify20: Validate incoming FID in FAN_FS_ERROR
On Tue, Oct 26, 2021 at 9:43 PM Gabriel Krisman Bertazi
<krisman@...labora.com> wrote:
>
> Verify the FID provided in the event. If the FH has size 0, this is
> assumed to be a superblock error (i.e. null FH).
>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@...labora.com>
Reviewed-by: Amir Goldstein <amir73il@...il.com>
Except maybe move define of FILEID_INVALID to header.
>
> ---
> Changes since v1:
> - Move defines to header file.
> - Use 0-len FH for sb error
> ---
> testcases/kernel/syscalls/fanotify/fanotify.h | 4 ++
> .../kernel/syscalls/fanotify/fanotify20.c | 63 +++++++++++++++++++
> 2 files changed, 67 insertions(+)
>
> diff --git a/testcases/kernel/syscalls/fanotify/fanotify.h b/testcases/kernel/syscalls/fanotify/fanotify.h
> index 58e30aaf00bc..9bff3cf1a3fe 100644
> --- a/testcases/kernel/syscalls/fanotify/fanotify.h
> +++ b/testcases/kernel/syscalls/fanotify/fanotify.h
> @@ -435,4 +435,8 @@ struct fanotify_event_info_header *get_event_info(
> ((struct fanotify_event_info_error *) \
> get_event_info((event), FAN_EVENT_INFO_TYPE_ERROR))
>
> +#define get_event_info_fid(event) \
> + ((struct fanotify_event_info_fid *) \
> + get_event_info((event), FAN_EVENT_INFO_TYPE_FID))
> +
> #endif /* __FANOTIFY_H__ */
> diff --git a/testcases/kernel/syscalls/fanotify/fanotify20.c b/testcases/kernel/syscalls/fanotify/fanotify20.c
> index 6074d449ae63..220cd51419e8 100644
> --- a/testcases/kernel/syscalls/fanotify/fanotify20.c
> +++ b/testcases/kernel/syscalls/fanotify/fanotify20.c
> @@ -34,20 +34,61 @@
> #ifdef HAVE_SYS_FANOTIFY_H
> #include "fanotify.h"
>
> +#ifndef FILEID_INVALID
> +#define FILEID_INVALID 0xff
> +#endif
> +
> #define BUF_SIZE 256
> static char event_buf[BUF_SIZE];
> int fd_notify;
>
> #define MOUNT_PATH "test_mnt"
>
> +/* These expected FIDs are common to multiple tests */
> +static struct fanotify_fid_t null_fid;
> +
> static struct test_case {
> char *name;
> int error;
> unsigned int error_count;
> + struct fanotify_fid_t *fid;
> void (*trigger_error)(void);
> } testcases[] = {
> };
>
> +int check_error_event_info_fid(struct fanotify_event_info_fid *fid,
> + const struct test_case *ex)
> +{
> + struct file_handle *fh = (struct file_handle *) &fid->handle;
> +
> + if (memcmp(&fid->fsid, &ex->fid->fsid, sizeof(fid->fsid))) {
> + tst_res(TFAIL, "%s: Received bad FSID type (%x...!=%x...)",
> + ex->name, FSID_VAL_MEMBER(fid->fsid, 0),
> + FSID_VAL_MEMBER(ex->fid->fsid, 0));
> +
> + return 1;
> + }
> + if (fh->handle_type != ex->fid->handle.handle_type) {
> + tst_res(TFAIL, "%s: Received bad file_handle type (%d!=%d)",
> + ex->name, fh->handle_type, ex->fid->handle.handle_type);
> + return 1;
> + }
> +
> + if (fh->handle_bytes != ex->fid->handle.handle_bytes) {
> + tst_res(TFAIL, "%s: Received bad file_handle len (%d!=%d)",
> + ex->name, fh->handle_bytes, ex->fid->handle.handle_bytes);
> + return 1;
> + }
> +
> + if (memcmp(fh->f_handle, ex->fid->handle.f_handle, fh->handle_bytes)) {
> + tst_res(TFAIL, "%s: Received wrong handle. "
> + "Expected (%x...) got (%x...) ", ex->name,
> + *(int*)ex->fid->handle.f_handle, *(int*)fh->f_handle);
> + return 1;
> + }
> + return 0;
> +}
> +
> int check_error_event_info_error(struct fanotify_event_info_error *info_error,
> const struct test_case *ex)
> {
> @@ -91,6 +132,7 @@ void check_event(char *buf, size_t len, const struct test_case *ex)
> struct fanotify_event_metadata *event =
> (struct fanotify_event_metadata *) buf;
> struct fanotify_event_info_error *info_error;
> + struct fanotify_event_info_fid *info_fid;
> int fail = 0;
>
> if (len < FAN_EVENT_METADATA_LEN) {
> @@ -109,6 +151,14 @@ void check_event(char *buf, size_t len, const struct test_case *ex)
> fail++;
> }
>
> + info_fid = get_event_info_fid(event);
> + if (info_fid)
> + fail += check_error_event_info_fid(info_fid, ex);
> + else {
> + tst_res(TFAIL, "FID record not found");
> + fail++;
> + }
> +
> if (!fail)
> tst_res(TPASS, "Successfully received: %s", ex->name);
> }
> @@ -125,12 +175,25 @@ static void do_test(unsigned int i)
> check_event(event_buf, read_len, tcase);
> }
>
> +static void init_null_fid(void)
> +{
> + /* Use fanotify_save_fid to fill the fsid and overwrite the
> + * file_handler to create a null_fid
> + */
> + fanotify_save_fid(MOUNT_PATH, &null_fid);
> +
> + null_fid.handle.handle_type = FILEID_INVALID;
> + null_fid.handle.handle_bytes = 0;
> +}
> +
> static void setup(void)
> {
> REQUIRE_FANOTIFY_EVENTS_SUPPORTED_ON_FS(FAN_CLASS_NOTIF|FAN_REPORT_FID,
> FAN_MARK_FILESYSTEM,
> FAN_FS_ERROR, ".");
>
> + init_null_fid();
> +
> fd_notify = SAFE_FANOTIFY_INIT(FAN_CLASS_NOTIF|FAN_REPORT_FID,
> O_RDONLY);
>
> --
> 2.33.0
>
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