6.6-stable review patch. If anyone has any objections, please let me know.
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From: Paulo Alcantara pc@manguebit.com
commit 93cee45ccfebc62a3bb4cd622b89e00c8c7d8493 upstream.
Serialise cifs_construct_tcon() with cifs_mount_mutex to handle parallel mounts that may end up reusing the session and tcon created by it.
Cc: stable@vger.kernel.org # 6.4+ Signed-off-by: Paulo Alcantara (Red Hat) pc@manguebit.com Signed-off-by: Steve French stfrench@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/smb/client/connect.c | 13 ++++++++++++- fs/smb/client/fs_context.c | 6 +++--- fs/smb/client/fs_context.h | 12 ++++++++++++ 3 files changed, 27 insertions(+), 4 deletions(-)
--- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -3981,7 +3981,7 @@ cifs_set_vol_auth(struct smb3_fs_context }
static struct cifs_tcon * -cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid) +__cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid) { int rc; struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb); @@ -4079,6 +4079,17 @@ out: return tcon; }
+static struct cifs_tcon * +cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid) +{ + struct cifs_tcon *ret; + + cifs_mount_lock(); + ret = __cifs_construct_tcon(cifs_sb, fsuid); + cifs_mount_unlock(); + return ret; +} + struct cifs_tcon * cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb) { --- a/fs/smb/client/fs_context.c +++ b/fs/smb/client/fs_context.c @@ -37,7 +37,7 @@ #include "rfc1002pdu.h" #include "fs_context.h"
-static DEFINE_MUTEX(cifs_mount_mutex); +DEFINE_MUTEX(cifs_mount_mutex);
static const match_table_t cifs_smb_version_tokens = { { Smb_1, SMB1_VERSION_STRING }, @@ -752,9 +752,9 @@ static int smb3_get_tree(struct fs_conte
if (err) return err; - mutex_lock(&cifs_mount_mutex); + cifs_mount_lock(); ret = smb3_get_tree_common(fc); - mutex_unlock(&cifs_mount_mutex); + cifs_mount_unlock(); return ret; }
--- a/fs/smb/client/fs_context.h +++ b/fs/smb/client/fs_context.h @@ -293,4 +293,16 @@ extern void smb3_update_mnt_flags(struct #define MAX_CACHED_FIDS 16 extern char *cifs_sanitize_prepath(char *prepath, gfp_t gfp);
+extern struct mutex cifs_mount_mutex; + +static inline void cifs_mount_lock(void) +{ + mutex_lock(&cifs_mount_mutex); +} + +static inline void cifs_mount_unlock(void) +{ + mutex_unlock(&cifs_mount_mutex); +} + #endif