diff options
| author | Shyam Prasad N <sprasad@microsoft.com> | 2023-02-20 13:02:11 +0000 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2023-03-22 23:15:40 -0500 |
| commit | 2f4e429c846972c8405951a9ff7a82aceeca7461 (patch) | |
| tree | 1c7ce858d3bd5422746f717fc54be8c74dc69375 /fs/cifs/connect.c | |
| parent | 2f0e4f0342201fe2228fcc2301cc2b42ae04b8e3 (diff) | |
cifs: lock chan_lock outside match_session
Coverity had rightly indicated a possible deadlock
due to chan_lock being done inside match_session.
All callers of match_* functions should pick up the
necessary locks and call them.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Cc: stable@vger.kernel.org
Fixes: 724244cdb382 ("cifs: protect session channel fields with chan_lock")
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/cifs/connect.c')
| -rw-r--r-- | fs/cifs/connect.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 49b37594e991..f42cc7077312 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -1721,7 +1721,7 @@ out_err: return ERR_PTR(rc); } -/* this function must be called with ses_lock held */ +/* this function must be called with ses_lock and chan_lock held */ static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx) { if (ctx->sectype != Unspecified && @@ -1732,12 +1732,8 @@ static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx) * If an existing session is limited to less channels than * requested, it should not be reused */ - spin_lock(&ses->chan_lock); - if (ses->chan_max < ctx->max_channels) { - spin_unlock(&ses->chan_lock); + if (ses->chan_max < ctx->max_channels) return 0; - } - spin_unlock(&ses->chan_lock); switch (ses->sectype) { case Kerberos: @@ -1865,10 +1861,13 @@ cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx) spin_unlock(&ses->ses_lock); continue; } + spin_lock(&ses->chan_lock); if (!match_session(ses, ctx)) { + spin_unlock(&ses->chan_lock); spin_unlock(&ses->ses_lock); continue; } + spin_unlock(&ses->chan_lock); spin_unlock(&ses->ses_lock); ++ses->ses_count; @@ -2693,6 +2692,7 @@ cifs_match_super(struct super_block *sb, void *data) spin_lock(&tcp_srv->srv_lock); spin_lock(&ses->ses_lock); + spin_lock(&ses->chan_lock); spin_lock(&tcon->tc_lock); if (!match_server(tcp_srv, ctx, dfs_super_cmp) || !match_session(ses, ctx) || @@ -2705,6 +2705,7 @@ cifs_match_super(struct super_block *sb, void *data) rc = compare_mount_options(sb, mnt_data); out: spin_unlock(&tcon->tc_lock); + spin_unlock(&ses->chan_lock); spin_unlock(&ses->ses_lock); spin_unlock(&tcp_srv->srv_lock); |