From 4214ebf4654798309364d0c678b799e402f38288 Mon Sep 17 00:00:00 2001 From: Sachin Prabhu Date: Fri, 29 Jul 2016 22:38:19 +0100 Subject: Fix memory leaks in cifs_do_mount() Fix memory leaks introduced by the patch fs/cifs: make share unaccessible at root level mountable Also move allocation of cifs_sb->prepath to cifs_setup_cifs_sb(). Signed-off-by: Sachin Prabhu Tested-by: Aurelien Aptel Signed-off-by: Steve French --- fs/cifs/cifsfs.c | 20 ++++++++------------ fs/cifs/cifsproto.h | 2 +- fs/cifs/connect.c | 10 +++++++++- 3 files changed, 18 insertions(+), 14 deletions(-) (limited to 'fs') diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 6bbec5e784cd..cc9cdab52dab 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -686,26 +686,22 @@ cifs_do_mount(struct file_system_type *fs_type, cifs_sb->mountdata = kstrndup(data, PAGE_SIZE, GFP_KERNEL); if (cifs_sb->mountdata == NULL) { root = ERR_PTR(-ENOMEM); - goto out_cifs_sb; + goto out_free; } - if (volume_info->prepath) { - cifs_sb->prepath = kstrdup(volume_info->prepath, GFP_KERNEL); - if (cifs_sb->prepath == NULL) { - root = ERR_PTR(-ENOMEM); - goto out_cifs_sb; - } + rc = cifs_setup_cifs_sb(volume_info, cifs_sb); + if (rc) { + root = ERR_PTR(rc); + goto out_free; } - cifs_setup_cifs_sb(volume_info, cifs_sb); - rc = cifs_mount(cifs_sb, volume_info); if (rc) { if (!(flags & MS_SILENT)) cifs_dbg(VFS, "cifs_mount failed w/return code = %d\n", rc); root = ERR_PTR(rc); - goto out_mountdata; + goto out_free; } mnt_data.vol = volume_info; @@ -752,9 +748,9 @@ out: cifs_cleanup_volume_info(volume_info); return root; -out_mountdata: +out_free: + kfree(cifs_sb->prepath); kfree(cifs_sb->mountdata); -out_cifs_sb: kfree(cifs_sb); out_nls: unload_nls(volume_info->local_nls); diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index 1243bd326591..95dab43646f0 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -184,7 +184,7 @@ extern int cifs_read_from_socket(struct TCP_Server_Info *server, char *buf, unsigned int to_read); extern int cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page, unsigned int to_read); -extern void cifs_setup_cifs_sb(struct smb_vol *pvolume_info, +extern int cifs_setup_cifs_sb(struct smb_vol *pvolume_info, struct cifs_sb_info *cifs_sb); extern int cifs_match_super(struct super_block *, void *); extern void cifs_cleanup_volume_info(struct smb_vol *pvolume_info); diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 7ae03283bd61..4546926680d4 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -3222,7 +3222,7 @@ void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon, } } -void cifs_setup_cifs_sb(struct smb_vol *pvolume_info, +int cifs_setup_cifs_sb(struct smb_vol *pvolume_info, struct cifs_sb_info *cifs_sb) { INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks); @@ -3316,6 +3316,14 @@ void cifs_setup_cifs_sb(struct smb_vol *pvolume_info, if ((pvolume_info->cifs_acl) && (pvolume_info->dynperm)) cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n"); + + if (pvolume_info->prepath) { + cifs_sb->prepath = kstrdup(pvolume_info->prepath, GFP_KERNEL); + if (cifs_sb->prepath == NULL) + return -ENOMEM; + } + + return 0; } static void -- cgit From c1d8b24d18192764fe82067ec6aa8d4c3bf094e0 Mon Sep 17 00:00:00 2001 From: Sachin Prabhu Date: Fri, 29 Jul 2016 22:38:20 +0100 Subject: Compare prepaths when comparing superblocks The patch fs/cifs: make share unaccessible at root level mountable makes use of prepaths when any component of the underlying path is inaccessible. When mounting 2 separate shares having different prepaths but are other wise similar in other respects, we end up sharing superblocks when we shouldn't be doing so. Signed-off-by: Sachin Prabhu Tested-by: Aurelien Aptel Signed-off-by: Steve French --- fs/cifs/connect.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 4546926680d4..2e4f4bad8b1e 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2781,6 +2781,24 @@ compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data) return 1; } +static int +match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data) +{ + struct cifs_sb_info *old = CIFS_SB(sb); + struct cifs_sb_info *new = mnt_data->cifs_sb; + + if (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) { + if (!(new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)) + return 0; + /* The prepath should be null terminated strings */ + if (strcmp(new->prepath, old->prepath)) + return 0; + + return 1; + } + return 0; +} + int cifs_match_super(struct super_block *sb, void *data) { @@ -2808,7 +2826,8 @@ cifs_match_super(struct super_block *sb, void *data) if (!match_server(tcp_srv, volume_info) || !match_session(ses, volume_info) || - !match_tcon(tcon, volume_info->UNC)) { + !match_tcon(tcon, volume_info->UNC) || + !match_prepath(sb, mnt_data)) { rc = 0; goto out; } -- cgit From 348c1bfa84dfc47da1f1234b7f2bf09fa798edea Mon Sep 17 00:00:00 2001 From: Sachin Prabhu Date: Fri, 29 Jul 2016 22:38:21 +0100 Subject: Move check for prefix path to within cifs_get_root() Signed-off-by: Sachin Prabhu Tested-by: Aurelien Aptel Signed-off-by: Steve French --- fs/cifs/cifsfs.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'fs') diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index cc9cdab52dab..14ae4b8e1a3c 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -609,6 +609,9 @@ cifs_get_root(struct smb_vol *vol, struct super_block *sb) char *s, *p; char sep; + if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) + return dget(sb->s_root); + full_path = cifs_build_path_to_root(vol, cifs_sb, cifs_sb_master_tcon(cifs_sb)); if (full_path == NULL) @@ -731,11 +734,7 @@ cifs_do_mount(struct file_system_type *fs_type, sb->s_flags |= MS_ACTIVE; } - if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) - root = dget(sb->s_root); - else - root = cifs_get_root(volume_info, sb); - + root = cifs_get_root(volume_info, sb); if (IS_ERR(root)) goto out_super; -- cgit