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| author | Paulo Alcantara <pc@cjr.nz> | 2020-11-28 16:54:02 -0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-12-11 13:25:01 +0100 |
| commit | ba54b13c835609b3976714d3dde010c57d0fe23e (patch) | |
| tree | f4b26ad79b9f4d7d1193f67d4e7f43fbe0e93e85 | |
| parent | 73b14c21c5dce6046daff0cc8965226581eb6681 (diff) | |
| download | linux-stable-ba54b13c835609b3976714d3dde010c57d0fe23e.tar.gz linux-stable-ba54b13c835609b3976714d3dde010c57d0fe23e.tar.bz2 linux-stable-ba54b13c835609b3976714d3dde010c57d0fe23e.zip | |
cifs: fix potential use-after-free in cifs_echo_request()
commit 212253367dc7b49ed3fc194ce71b0992eacaecf2 upstream.
This patch fixes a potential use-after-free bug in
cifs_echo_request().
For instance,
thread 1
--------
cifs_demultiplex_thread()
clean_demultiplex_info()
kfree(server)
thread 2 (workqueue)
--------
apic_timer_interrupt()
smp_apic_timer_interrupt()
irq_exit()
__do_softirq()
run_timer_softirq()
call_timer_fn()
cifs_echo_request() <- use-after-free in server ptr
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/cifs/connect.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 6335ca143292..6285085195c1 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -777,6 +777,8 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server) list_del_init(&server->tcp_ses_list); spin_unlock(&cifs_tcp_ses_lock); + cancel_delayed_work_sync(&server->echo); + spin_lock(&GlobalMid_Lock); server->tcpStatus = CifsExiting; spin_unlock(&GlobalMid_Lock); |