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| author | Paulo Alcantara <pc@cjr.nz> | 2021-05-03 17:55:26 +0300 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2021-05-04 19:52:56 +0300 |
| commit | 5c1acf3fe05ce443edba5e2110c9e581765f66a8 (patch) | |
| tree | 657dbc77464a9b56673aa149e13ba98a95be6b8c /fs/cifs/fs_context.c | |
| parent | 5b2abdafbedb902d7d8d3d5e571a38b8900dd15f (diff) | |
| download | linux-5c1acf3fe05ce443edba5e2110c9e581765f66a8.tar.xz | |
cifs: fix regression when mounting shares with prefix paths
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>
Acked-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/cifs/fs_context.c')
| -rw-r--r-- | fs/cifs/fs_context.c | 4 |
1 files changed, 4 insertions, 0 deletions
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; |