* [PATCH] cifs: fix regression when mounting shares with prefix paths
@ 2021-04-30 22:16 Paulo Alcantara
2021-04-30 23:40 ` David Disseldorp
2021-05-03 14:55 ` [PATCH v2] " Paulo Alcantara
0 siblings, 2 replies; 7+ messages in thread
From: Paulo Alcantara @ 2021-04-30 22:16 UTC (permalink / raw)
To: linux-cifs, smfrench; +Cc: ddiss, aaptel, Paulo Alcantara, stable
The commit 315db9a05b7a ("cifs: fix leak in cifs_smb3_do_mount() ctx")
revealed an existing bug when mounting shares that contain a prefix
path or DFS links.
cifs_setup_volume_info() requires the @devname to contain the full
path (UNC + prefix) to update the fs context with the new UNC and
prepath values, however we were passing only the UNC
path (old_ctx->UNC) in @device thus discarding any prefix paths.
Instead of concatenating both old_ctx->{UNC,prepath} and pass it in
@devname, just keep the dup'ed values of UNC and prepath in
cifs_sb->ctx after calling smb3_fs_context_dup(), and fix
smb3_parse_devname() to correctly parse and not leak the new UNC and
prefix paths.
Cc: <stable@vger.kernel.org> # v5.11+
Fixes: 315db9a05b7a ("cifs: fix leak in cifs_smb3_do_mount() ctx")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
---
fs/cifs/cifsfs.c | 8 +-------
fs/cifs/connect.c | 25 +++++++++++++++++--------
fs/cifs/fs_context.c | 4 ++++
3 files changed, 22 insertions(+), 15 deletions(-)
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 8a6894577697..d7ea9c5fe0f8 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -863,13 +863,7 @@ cifs_smb3_do_mount(struct file_system_type *fs_type,
goto out;
}
- /* cifs_setup_volume_info->smb3_parse_devname() redups UNC & prepath */
- kfree(cifs_sb->ctx->UNC);
- cifs_sb->ctx->UNC = NULL;
- kfree(cifs_sb->ctx->prepath);
- cifs_sb->ctx->prepath = NULL;
-
- rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, old_ctx->UNC);
+ rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, NULL);
if (rc) {
root = ERR_PTR(rc);
goto out;
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index becd5f807787..04a06e22e715 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3159,19 +3159,28 @@ static int do_dfs_failover(const char *path, const char *full_path, struct cifs_
int
cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
{
- int rc = 0;
+ int rc;
- smb3_parse_devname(devname, ctx);
+ if (devname) {
+ cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname);
+ rc = smb3_parse_devname(devname, ctx);
+ if (rc) {
+ cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc);
+ return rc;
+ }
+ }
if (mntopts) {
char *ip;
- cifs_dbg(FYI, "%s: mntopts=%s\n", __func__, mntopts);
rc = smb3_parse_opt(mntopts, "ip", &ip);
- if (!rc && !cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip,
- strlen(ip))) {
- cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
- return -EINVAL;
+ if (!rc) {
+ rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
+ kfree(ip);
+ if (!rc) {
+ cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
+ return -EINVAL;
+ }
}
}
@@ -3189,7 +3198,7 @@ cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const c
return -EINVAL;
}
- return rc;
+ return 0;
}
static int
diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c
index 1d6e0e15b034..3bcf881c3ae9 100644
--- a/fs/cifs/fs_context.c
+++ b/fs/cifs/fs_context.c
@@ -476,6 +476,7 @@ smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx)
/* move "pos" up to delimiter or NULL */
pos += len;
+ kfree(ctx->UNC);
ctx->UNC = kstrndup(devname, pos - devname, GFP_KERNEL);
if (!ctx->UNC)
return -ENOMEM;
@@ -486,6 +487,9 @@ smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx)
if (*pos == '/' || *pos == '\\')
pos++;
+ kfree(ctx->prepath);
+ ctx->prepath = NULL;
+
/* If pos is NULL then no prepath */
if (!*pos)
return 0;
--
2.31.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH] cifs: fix regression when mounting shares with prefix paths
2021-04-30 22:16 [PATCH] cifs: fix regression when mounting shares with prefix paths Paulo Alcantara
@ 2021-04-30 23:40 ` David Disseldorp
2021-05-03 12:41 ` Paulo Alcantara
2021-05-03 14:55 ` [PATCH v2] " Paulo Alcantara
1 sibling, 1 reply; 7+ messages in thread
From: David Disseldorp @ 2021-04-30 23:40 UTC (permalink / raw)
To: Paulo Alcantara; +Cc: linux-cifs, smfrench, aaptel, stable
On Fri, 30 Apr 2021 19:16:21 -0300, Paulo Alcantara wrote:
> The commit 315db9a05b7a ("cifs: fix leak in cifs_smb3_do_mount() ctx")
> revealed an existing bug when mounting shares that contain a prefix
> path or DFS links.
Sorry for the mess. One question...
...
> if (mntopts) {
> char *ip;
>
> - cifs_dbg(FYI, "%s: mntopts=%s\n", __func__, mntopts);
> rc = smb3_parse_opt(mntopts, "ip", &ip);
> - if (!rc && !cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip,
> - strlen(ip))) {
> - cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
> - return -EINVAL;
> + if (!rc) {
> + rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
> + kfree(ip);
> + if (!rc) {
> + cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
> + return -EINVAL;
> + }
> }
> }
>
> @@ -3189,7 +3198,7 @@ cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const c
> return -EINVAL;
> }
>
> - return rc;
> + return 0;
> }
It seems that smb3_parse_opt() errors will no longer be propagated here.
Is that intentional?
Cheers, David
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] cifs: fix regression when mounting shares with prefix paths
2021-04-30 23:40 ` David Disseldorp
@ 2021-05-03 12:41 ` Paulo Alcantara
0 siblings, 0 replies; 7+ messages in thread
From: Paulo Alcantara @ 2021-05-03 12:41 UTC (permalink / raw)
To: David Disseldorp; +Cc: linux-cifs, smfrench, aaptel, stable
David Disseldorp <ddiss@suse.de> writes:
> On Fri, 30 Apr 2021 19:16:21 -0300, Paulo Alcantara wrote:
>
>> The commit 315db9a05b7a ("cifs: fix leak in cifs_smb3_do_mount() ctx")
>> revealed an existing bug when mounting shares that contain a prefix
>> path or DFS links.
>
> Sorry for the mess. One question...
>
> ...
>> if (mntopts) {
>> char *ip;
>>
>> - cifs_dbg(FYI, "%s: mntopts=%s\n", __func__, mntopts);
>> rc = smb3_parse_opt(mntopts, "ip", &ip);
>> - if (!rc && !cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip,
>> - strlen(ip))) {
>> - cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
>> - return -EINVAL;
>> + if (!rc) {
>> + rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
>> + kfree(ip);
>> + if (!rc) {
>> + cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
>> + return -EINVAL;
>> + }
>> }
>> }
>>
>> @@ -3189,7 +3198,7 @@ cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const c
>> return -EINVAL;
>> }
>>
>> - return rc;
>> + return 0;
>> }
>
> It seems that smb3_parse_opt() errors will no longer be propagated here.
> Is that intentional?
That was a mistake, actually. Will fix it in v2. Thanks!
^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH v2] cifs: fix regression when mounting shares with prefix paths
2021-04-30 22:16 [PATCH] cifs: fix regression when mounting shares with prefix paths Paulo Alcantara
2021-04-30 23:40 ` David Disseldorp
@ 2021-05-03 14:55 ` Paulo Alcantara
2021-05-03 23:20 ` David Disseldorp
1 sibling, 1 reply; 7+ messages in thread
From: Paulo Alcantara @ 2021-05-03 14:55 UTC (permalink / raw)
To: linux-cifs, smfrench; +Cc: ddiss, aaptel, Paulo Alcantara, stable
The commit 315db9a05b7a ("cifs: fix leak in cifs_smb3_do_mount() ctx")
revealed an existing bug when mounting shares that contain a prefix
path or DFS links.
cifs_setup_volume_info() requires the @devname to contain the full
path (UNC + prefix) to update the fs context with the new UNC and
prepath values, however we were passing only the UNC
path (old_ctx->UNC) in @device thus discarding any prefix paths.
Instead of concatenating both old_ctx->{UNC,prepath} and pass it in
@devname, just keep the dup'ed values of UNC and prepath in
cifs_sb->ctx after calling smb3_fs_context_dup(), and fix
smb3_parse_devname() to correctly parse and not leak the new UNC and
prefix paths.
Cc: <stable@vger.kernel.org> # v5.11+
Fixes: 315db9a05b7a ("cifs: fix leak in cifs_smb3_do_mount() ctx")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
---
fs/cifs/cifsfs.c | 8 +-------
fs/cifs/connect.c | 24 ++++++++++++++++++------
fs/cifs/fs_context.c | 4 ++++
3 files changed, 23 insertions(+), 13 deletions(-)
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 8a6894577697..d7ea9c5fe0f8 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -863,13 +863,7 @@ cifs_smb3_do_mount(struct file_system_type *fs_type,
goto out;
}
- /* cifs_setup_volume_info->smb3_parse_devname() redups UNC & prepath */
- kfree(cifs_sb->ctx->UNC);
- cifs_sb->ctx->UNC = NULL;
- kfree(cifs_sb->ctx->prepath);
- cifs_sb->ctx->prepath = NULL;
-
- rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, old_ctx->UNC);
+ rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, NULL);
if (rc) {
root = ERR_PTR(rc);
goto out;
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index becd5f807787..4ce6fc24cae1 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -3159,17 +3159,29 @@ static int do_dfs_failover(const char *path, const char *full_path, struct cifs_
int
cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
{
- int rc = 0;
+ int rc;
- smb3_parse_devname(devname, ctx);
+ if (devname) {
+ cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname);
+ rc = smb3_parse_devname(devname, ctx);
+ if (rc) {
+ cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc);
+ return rc;
+ }
+ }
if (mntopts) {
char *ip;
- cifs_dbg(FYI, "%s: mntopts=%s\n", __func__, mntopts);
rc = smb3_parse_opt(mntopts, "ip", &ip);
- if (!rc && !cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip,
- strlen(ip))) {
+ if (rc) {
+ cifs_dbg(VFS, "%s: failed to parse ip options: %d\n", __func__, rc);
+ return rc;
+ }
+
+ rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
+ kfree(ip);
+ if (!rc) {
cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
return -EINVAL;
}
@@ -3189,7 +3201,7 @@ cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const c
return -EINVAL;
}
- return rc;
+ return 0;
}
static int
diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c
index 1d6e0e15b034..3bcf881c3ae9 100644
--- a/fs/cifs/fs_context.c
+++ b/fs/cifs/fs_context.c
@@ -476,6 +476,7 @@ smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx)
/* move "pos" up to delimiter or NULL */
pos += len;
+ kfree(ctx->UNC);
ctx->UNC = kstrndup(devname, pos - devname, GFP_KERNEL);
if (!ctx->UNC)
return -ENOMEM;
@@ -486,6 +487,9 @@ smb3_parse_devname(const char *devname, struct smb3_fs_context *ctx)
if (*pos == '/' || *pos == '\\')
pos++;
+ kfree(ctx->prepath);
+ ctx->prepath = NULL;
+
/* If pos is NULL then no prepath */
if (!*pos)
return 0;
--
2.31.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH v2] cifs: fix regression when mounting shares with prefix paths
2021-05-03 14:55 ` [PATCH v2] " Paulo Alcantara
@ 2021-05-03 23:20 ` David Disseldorp
2021-05-04 16:47 ` Paulo Alcantara
2021-05-04 16:58 ` Steve French
0 siblings, 2 replies; 7+ messages in thread
From: David Disseldorp @ 2021-05-03 23:20 UTC (permalink / raw)
To: Paulo Alcantara; +Cc: linux-cifs, smfrench, aaptel, stable
On Mon, 3 May 2021 11:55:26 -0300, Paulo Alcantara wrote:
> The commit 315db9a05b7a ("cifs: fix leak in cifs_smb3_do_mount() ctx")
> revealed an existing bug when mounting shares that contain a prefix
> path or DFS links.
>
> cifs_setup_volume_info() requires the @devname to contain the full
> path (UNC + prefix) to update the fs context with the new UNC and
> prepath values, however we were passing only the UNC
> path (old_ctx->UNC) in @device thus discarding any prefix paths.
>
> Instead of concatenating both old_ctx->{UNC,prepath} and pass it in
> @devname, just keep the dup'ed values of UNC and prepath in
> cifs_sb->ctx after calling smb3_fs_context_dup(), and fix
> smb3_parse_devname() to correctly parse and not leak the new UNC and
> prefix paths.
>
> Cc: <stable@vger.kernel.org> # v5.11+
> Fixes: 315db9a05b7a ("cifs: fix leak in cifs_smb3_do_mount() ctx")
> Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
> ---
> fs/cifs/cifsfs.c | 8 +-------
> fs/cifs/connect.c | 24 ++++++++++++++++++------
> fs/cifs/fs_context.c | 4 ++++
> 3 files changed, 23 insertions(+), 13 deletions(-)
>
> diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
> index 8a6894577697..d7ea9c5fe0f8 100644
> --- a/fs/cifs/cifsfs.c
> +++ b/fs/cifs/cifsfs.c
> @@ -863,13 +863,7 @@ cifs_smb3_do_mount(struct file_system_type *fs_type,
> goto out;
> }
>
> - /* cifs_setup_volume_info->smb3_parse_devname() redups UNC & prepath */
> - kfree(cifs_sb->ctx->UNC);
> - cifs_sb->ctx->UNC = NULL;
> - kfree(cifs_sb->ctx->prepath);
> - cifs_sb->ctx->prepath = NULL;
> -
> - rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, old_ctx->UNC);
> + rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, NULL);
IIUC, with the new behaviour, this call becomes pretty much an
if (!cifs_sb->ctx->username)
root = ERR_PTR(-EINVAL);
So it might be worth simplifying this further. Either way:
Acked-by: David Disseldorp <ddiss@suse.de>
Cheers, David
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH v2] cifs: fix regression when mounting shares with prefix paths
2021-05-03 23:20 ` David Disseldorp
@ 2021-05-04 16:47 ` Paulo Alcantara
2021-05-04 16:58 ` Steve French
1 sibling, 0 replies; 7+ messages in thread
From: Paulo Alcantara @ 2021-05-04 16:47 UTC (permalink / raw)
To: David Disseldorp; +Cc: linux-cifs, smfrench, aaptel, stable
David Disseldorp <ddiss@suse.de> writes:
> On Mon, 3 May 2021 11:55:26 -0300, Paulo Alcantara wrote:
>> - rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, old_ctx->UNC);
>> + rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, NULL);
>
> IIUC, with the new behaviour, this call becomes pretty much an
> if (!cifs_sb->ctx->username)
> root = ERR_PTR(-EINVAL);
Yeah. We should get rid of the damn thing at some point. I've just
tried to keep the logic we currently have in fs/cifs/connect.c by
composing new options based upon the chased DFS referrals.
Thanks for pointing it out!
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] cifs: fix regression when mounting shares with prefix paths
2021-05-03 23:20 ` David Disseldorp
2021-05-04 16:47 ` Paulo Alcantara
@ 2021-05-04 16:58 ` Steve French
1 sibling, 0 replies; 7+ messages in thread
From: Steve French @ 2021-05-04 16:58 UTC (permalink / raw)
To: David Disseldorp; +Cc: Paulo Alcantara, CIFS, Aurélien Aptel, Stable
added acked-by and merged into cifs-2.6.git for-next
On Mon, May 3, 2021 at 6:20 PM David Disseldorp <ddiss@suse.de> wrote:
>
> On Mon, 3 May 2021 11:55:26 -0300, Paulo Alcantara wrote:
>
> > The commit 315db9a05b7a ("cifs: fix leak in cifs_smb3_do_mount() ctx")
> > revealed an existing bug when mounting shares that contain a prefix
> > path or DFS links.
> >
> > cifs_setup_volume_info() requires the @devname to contain the full
> > path (UNC + prefix) to update the fs context with the new UNC and
> > prepath values, however we were passing only the UNC
> > path (old_ctx->UNC) in @device thus discarding any prefix paths.
> >
> > Instead of concatenating both old_ctx->{UNC,prepath} and pass it in
> > @devname, just keep the dup'ed values of UNC and prepath in
> > cifs_sb->ctx after calling smb3_fs_context_dup(), and fix
> > smb3_parse_devname() to correctly parse and not leak the new UNC and
> > prefix paths.
> >
> > Cc: <stable@vger.kernel.org> # v5.11+
> > Fixes: 315db9a05b7a ("cifs: fix leak in cifs_smb3_do_mount() ctx")
> > Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
> > ---
> > fs/cifs/cifsfs.c | 8 +-------
> > fs/cifs/connect.c | 24 ++++++++++++++++++------
> > fs/cifs/fs_context.c | 4 ++++
> > 3 files changed, 23 insertions(+), 13 deletions(-)
> >
> > diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
> > index 8a6894577697..d7ea9c5fe0f8 100644
> > --- a/fs/cifs/cifsfs.c
> > +++ b/fs/cifs/cifsfs.c
> > @@ -863,13 +863,7 @@ cifs_smb3_do_mount(struct file_system_type *fs_type,
> > goto out;
> > }
> >
> > - /* cifs_setup_volume_info->smb3_parse_devname() redups UNC & prepath */
> > - kfree(cifs_sb->ctx->UNC);
> > - cifs_sb->ctx->UNC = NULL;
> > - kfree(cifs_sb->ctx->prepath);
> > - cifs_sb->ctx->prepath = NULL;
> > -
> > - rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, old_ctx->UNC);
> > + rc = cifs_setup_volume_info(cifs_sb->ctx, NULL, NULL);
>
> IIUC, with the new behaviour, this call becomes pretty much an
> if (!cifs_sb->ctx->username)
> root = ERR_PTR(-EINVAL);
>
> So it might be worth simplifying this further. Either way:
> Acked-by: David Disseldorp <ddiss@suse.de>
>
> Cheers, David
--
Thanks,
Steve
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2021-05-04 16:58 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-30 22:16 [PATCH] cifs: fix regression when mounting shares with prefix paths Paulo Alcantara
2021-04-30 23:40 ` David Disseldorp
2021-05-03 12:41 ` Paulo Alcantara
2021-05-03 14:55 ` [PATCH v2] " Paulo Alcantara
2021-05-03 23:20 ` David Disseldorp
2021-05-04 16:47 ` Paulo Alcantara
2021-05-04 16:58 ` Steve French
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).