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cifs: NULL out tcon, pSesInfo, and srvTcp pointers when chasing DFS referrals

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The scenario is this:

The kernel gets EREMOTE and starts chasing a DFS referral at mount time.
The tcon reference is put, which puts the session reference too, but
neither pointer is zeroed out.

The mount gets retried (goto try_mount_again) with new mount info.
Session setup fails fails and rc ends up being non-zero. The code then
falls through to the end and tries to put the previously freed tcon
pointer again.  Oops at: cifs_put_smb_ses+0x14/0xd0

Fix this by moving the initialization of the rc variable and the tcon,
pSesInfo and srvTcp pointers below the try_mount_again label. Also, add
a FreeXid() before the goto to prevent xid "leaks".

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reported-by: Gustavo Carvalho Homem <gustavo@angulosolido.pt>
CC: stable <stable@kernel.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This commit is contained in:
Jeff Layton 2009-12-03 08:09:41 -05:00 committed by Steve French
parent 29e553631b
commit a2934c7b36
1 changed files with 9 additions and 4 deletions
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13
fs/cifs/connect.c
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@ -2287,12 +2287,12 @@ int
cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
char *mount_data_global, const char *devname)
{
int rc = 0;
int rc;
int xid;
struct smb_vol *volume_info;
struct cifsSesInfo *pSesInfo = NULL;
struct cifsTconInfo *tcon = NULL;
struct TCP_Server_Info *srvTcp = NULL;
struct cifsSesInfo *pSesInfo;
struct cifsTconInfo *tcon;
struct TCP_Server_Info *srvTcp;
char *full_path;
char *mount_data = mount_data_global;
#ifdef CONFIG_CIFS_DFS_UPCALL
@ -2301,6 +2301,10 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
int referral_walks_count = 0;
try_mount_again:
#endif
rc = 0;
tcon = NULL;
pSesInfo = NULL;
srvTcp = NULL;
full_path = NULL;
xid = GetXid();
@ -2597,6 +2601,7 @@ remote_path_check:
cleanup_volume_info(&volume_info);
referral_walks_count++;
FreeXid(xid);
goto try_mount_again;
}
#else /* No DFS support, return error on mount */