| Message ID | 1379637388-14975-1-git-send-email-kamal@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 6771d01..38bced5 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -380,6 +380,7 @@ cifs_reconnect(struct TCP_Server_Info *server) try_to_freeze(); /* we should try only the port we connected to before */ + mutex_lock(&server->srv_mutex); rc = generic_ip_connect(server); if (rc) { cFYI(1, "reconnect error %d", rc); @@ -391,6 +392,7 @@ cifs_reconnect(struct TCP_Server_Info *server) server->tcpStatus = CifsNeedNegotiate; spin_unlock(&GlobalMid_Lock); } + mutex_unlock(&server->srv_mutex); } while (server->tcpStatus == CifsNeedReconnect); return rc;
This is a note to let you know that I have just added a patch titled cifs: ensure that srv_mutex is held when dealing with ssocket pointer to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.10. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 80e0620f85f1b462a2f28defb5dfb4bb1198455d Mon Sep 17 00:00:00 2001 From: Jeff Layton <jlayton@redhat.com> Date: Thu, 5 Sep 2013 08:38:10 -0400 Subject: cifs: ensure that srv_mutex is held when dealing with ssocket pointer commit 73e216a8a42c0ef3d08071705c946c38fdbe12b0 upstream. Oleksii reported that he had seen an oops similar to this: BUG: unable to handle kernel NULL pointer dereference at 0000000000000088 IP: [<ffffffff814dcc13>] sock_sendmsg+0x93/0xd0 PGD 0 Oops: 0000 [#1] PREEMPT SMP Modules linked in: ipt_MASQUERADE xt_REDIRECT xt_tcpudp iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack ip_tables x_tables carl9170 ath usb_storage f2fs nfnetlink_log nfnetlink md4 cifs dns_resolver hid_generic usbhid hid af_packet uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core videodev rfcomm btusb bnep bluetooth qmi_wwan qcserial cdc_wdm usb_wwan usbnet usbserial mii snd_hda_codec_hdmi snd_hda_codec_realtek iwldvm mac80211 coretemp intel_powerclamp kvm_intel kvm iwlwifi snd_hda_intel cfg80211 snd_hda_codec xhci_hcd e1000e ehci_pci snd_hwdep sdhci_pci snd_pcm ehci_hcd microcode psmouse sdhci thinkpad_acpi mmc_core i2c_i801 pcspkr usbcore hwmon snd_timer snd_page_alloc snd ptp rfkill pps_core soundcore evdev usb_common vboxnetflt(O) vboxdrv(O)Oops#2 Part8 loop tun binfmt_misc fuse msr acpi_call(O) ipv6 autofs4 CPU: 0 PID: 21612 Comm: kworker/0:1 Tainted: G W O 3.10.1SIGN #28 Hardware name: LENOVO 2306CTO/2306CTO, BIOS G2ET92WW (2.52 ) 02/22/2013 Workqueue: cifsiod cifs_echo_request [cifs] task: ffff8801e1f416f0 ti: ffff880148744000 task.ti: ffff880148744000 RIP: 0010:[<ffffffff814dcc13>] [<ffffffff814dcc13>] sock_sendmsg+0x93/0xd0 RSP: 0000:ffff880148745b00 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff880148745b78 RCX: 0000000000000048 RDX: ffff880148745c90 RSI: ffff880181864a00 RDI: ffff880148745b78 RBP: ffff880148745c48 R08: 0000000000000048 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff880181864a00 R13: ffff880148745c90 R14: 0000000000000048 R15: 0000000000000048 FS: 0000000000000000(0000) GS:ffff88021e200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000088 CR3: 000000020c42c000 CR4: 00000000001407b0 Oops#2 Part7 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffff880148745b30 ffffffff810c4af9 0000004848745b30 ffff880181864a00 ffffffff81ffbc40 0000000000000000 ffff880148745c90 ffffffff810a5aab ffff880148745bc0 ffffffff81ffbc40 ffff880148745b60 ffffffff815a9fb8 Call Trace: [<ffffffff810c4af9>] ? finish_task_switch+0x49/0xe0 [<ffffffff810a5aab>] ? lock_timer_base.isra.36+0x2b/0x50 [<ffffffff815a9fb8>] ? _raw_spin_unlock_irqrestore+0x18/0x40 [<ffffffff810a673f>] ? try_to_del_timer_sync+0x4f/0x70 [<ffffffff815aa38f>] ? _raw_spin_unlock_bh+0x1f/0x30 [<ffffffff814dcc87>] kernel_sendmsg+0x37/0x50 [<ffffffffa081a0e0>] smb_send_kvec+0xd0/0x1d0 [cifs] [<ffffffffa081a263>] smb_send_rqst+0x83/0x1f0 [cifs] [<ffffffffa081ab6c>] cifs_call_async+0xec/0x1b0 [cifs] [<ffffffffa08245e0>] ? free_rsp_buf+0x40/0x40 [cifs] Oops#2 Part6 [<ffffffffa082606e>] SMB2_echo+0x8e/0xb0 [cifs] [<ffffffffa0808789>] cifs_echo_request+0x79/0xa0 [cifs] [<ffffffff810b45b3>] process_one_work+0x173/0x4a0 [<ffffffff810b52a1>] worker_thread+0x121/0x3a0 [<ffffffff810b5180>] ? manage_workers.isra.27+0x2b0/0x2b0 [<ffffffff810bae00>] kthread+0xc0/0xd0 [<ffffffff810bad40>] ? kthread_create_on_node+0x120/0x120 [<ffffffff815b199c>] ret_from_fork+0x7c/0xb0 [<ffffffff810bad40>] ? kthread_create_on_node+0x120/0x120 Code: 84 24 b8 00 00 00 4c 89 f1 4c 89 ea 4c 89 e6 48 89 df 4c 89 60 18 48 c7 40 28 00 00 00 00 4c 89 68 30 44 89 70 14 49 8b 44 24 28 <ff> 90 88 00 00 00 3d ef fd ff ff 74 10 48 8d 65 e0 5b 41 5c 41 RIP [<ffffffff814dcc13>] sock_sendmsg+0x93/0xd0 RSP <ffff880148745b00> CR2: 0000000000000088 The client was in the middle of trying to send a frame when the server->ssocket pointer got zeroed out. In most places, that we access that pointer, the srv_mutex is held. There's only one spot that I see that the server->ssocket pointer gets set and the srv_mutex isn't held. This patch corrects that. The upstream bug report was here: https://bugzilla.kernel.org/show_bug.cgi?id=60557 Reported-by: Oleksii Shevchuk <alxchk@gmail.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- fs/cifs/connect.c | 2 ++ 1 file changed, 2 insertions(+) -- 1.8.1.2