CVE-2019-19965: git/torvalds/linux.git - Linux kernel source tree

author

Jason Yan [email protected]

2019-12-06 09:11:18 +0800

committer

Martin K. Petersen [email protected]

2019-12-09 19:15:52 -0500

commit

f70267f379b5e5e11bdc5d72a56bf17e5feed01f (patch)

tree

b5a843374ef222d0fcaf07b75ceaa8488cf23cb6

parent

d168001d14eccfda229b4a41a2c31a21e3c379da (diff)

download

linux-f70267f379b5e5e11bdc5d72a56bf17e5feed01f.tar.gz

scsi: libsas: stop discovering if oob mode is disconnected

The discovering of sas port is driven by workqueue in libsas. When libsas is processing port events or phy events in workqueue, new events may rise up and change the state of some structures such as asd_sas_phy. This may cause some problems such as follows: ==>thread 1 ==>thread 2 ==>phy up ==>phy_up_v3_hw() ==>oob_mode = SATA_OOB_MODE; ==>phy down quickly ==>hisi_sas_phy_down() ==>sas_ha->notify_phy_event() ==>sas_phy_disconnected() ==>oob_mode = OOB_NOT_CONNECTED ==>workqueue wakeup ==>sas_form_port() ==>sas_discover_domain() ==>sas_get_port_device() ==>oob_mode is OOB_NOT_CONNECTED and device is wrongly taken as expander This at last lead to the panic when libsas trying to issue a command to discover the device. [183047.614035] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058 [183047.622896] Mem abort info: [183047.625762] ESR = 0x96000004 [183047.628893] Exception class = DABT (current EL), IL = 32 bits [183047.634888] SET = 0, FnV = 0 [183047.638015] EA = 0, S1PTW = 0 [183047.641232] Data abort info: [183047.644189] ISV = 0, ISS = 0x00000004 [183047.648100] CM = 0, WnR = 0 [183047.651145] user pgtable: 4k pages, 48-bit VAs, pgdp = 00000000b7df67be [183047.657834] [0000000000000058] pgd=0000000000000000 [183047.662789] Internal error: Oops: 96000004 [#1] SMP [183047.667740] Process kworker/u16:2 (pid: 31291, stack limit = 0x00000000417c4974) [183047.675208] CPU: 0 PID: 3291 Comm: kworker/u16:2 Tainted: G W OE 4.19.36-vhulk1907.1.0.h410.eulerosv2r8.aarch64 #1 [183047.687015] Hardware name: N/A N/A/Kunpeng Desktop Board D920S10, BIOS 0.15 10/22/2019 [183047.695007] Workqueue: 0000:74:02.0_disco_q sas_discover_domain [183047.700999] pstate: 20c00009 (nzCv daif +PAN +UAO) [183047.705864] pc : prep_ata_v3_hw+0xf8/0x230 [hisi_sas_v3_hw] [183047.711510] lr : prep_ata_v3_hw+0xb0/0x230 [hisi_sas_v3_hw] [183047.717153] sp : ffff00000f28ba60 [183047.720541] x29: ffff00000f28ba60 x28: ffff8026852d7228 [183047.725925] x27: ffff8027dba3e0a8 x26: ffff8027c05fc200 [183047.731310] x25: 0000000000000000 x24: ffff8026bafa8dc0 [183047.736695] x23: ffff8027c05fc218 x22: ffff8026852d7228 [183047.742079] x21: ffff80007c2f2940 x20: ffff8027c05fc200 [183047.747464] x19: 0000000000f80800 x18: 0000000000000010 [183047.752848] x17: 0000000000000000 x16: 0000000000000000 [183047.758232] x15: ffff000089a5a4ff x14: 0000000000000005 [183047.763617] x13: ffff000009a5a50e x12: ffff8026bafa1e20 [183047.769001] x11: ffff0000087453b8 x10: ffff00000f28b870 [183047.774385] x9 : 0000000000000000 x8 : ffff80007e58f9b0 [183047.779770] x7 : 0000000000000000 x6 : 000000000000003f [183047.785154] x5 : 0000000000000040 x4 : ffffffffffffffe0 [183047.790538] x3 : 00000000000000f8 x2 : 0000000002000007 [183047.795922] x1 : 0000000000000008 x0 : 0000000000000000 [183047.801307] Call trace: [183047.803827] prep_ata_v3_hw+0xf8/0x230 [hisi_sas_v3_hw] [183047.809127] hisi_sas_task_prep+0x750/0x888 [hisi_sas_main] [183047.814773] hisi_sas_task_exec.isra.7+0x88/0x1f0 [hisi_sas_main] [183047.820939] hisi_sas_queue_command+0x28/0x38 [hisi_sas_main] [183047.826757] smp_execute_task_sg+0xec/0x218 [183047.831013] smp_execute_task+0x74/0xa0 [183047.834921] sas_discover_expander.part.7+0x9c/0x5f8 [183047.839959] sas_discover_root_expander+0x90/0x160 [183047.844822] sas_discover_domain+0x1b8/0x1e8 [183047.849164] process_one_work+0x1b4/0x3f8 [183047.853246] worker_thread+0x54/0x470 [183047.856981] kthread+0x134/0x138 [183047.860283] ret_from_fork+0x10/0x18 [183047.863931] Code: f9407a80 528000e2 39409281 72a04002 (b9405800) [183047.870097] kernel fault(0x1) notification starting on CPU 0 [183047.875828] kernel fault(0x1) notification finished on CPU 0 [183047.881559] Modules linked in: unibsp(OE) hns3(OE) hclge(OE) hnae3(OE) mem_drv(OE) hisi_sas_v3_hw(OE) hisi_sas_main(OE) [183047.892418] —[ end trace 4cc26083fc11b783 ]— [183047.897107] Kernel panic - not syncing: Fatal exception [183047.902403] kernel fault(0x5) notification starting on CPU 0 [183047.908134] kernel fault(0x5) notification finished on CPU 0 [183047.913865] SMP: stopping secondary CPUs [183047.917861] Kernel Offset: disabled [183047.921422] CPU features: 0x2,a2a00a38 [183047.925243] Memory Limit: none [183047.928372] kernel reboot(0x2) notification starting on CPU 0 [183047.934190] kernel reboot(0x2) notification finished on CPU 0 [183047.940008] —[ end Kernel panic - not syncing: Fatal exception ]— Fixes: 2908d778ab3e ("[SCSI] aic94xx: new driver") Link: https://lore.kernel.org/r/[email protected] Reported-by: Gao Chuan [email protected] Reviewed-by: John Garry [email protected] Signed-off-by: Jason Yan [email protected] Signed-off-by: Martin K. Petersen [email protected]

-rw-r–r--

drivers/scsi/libsas/sas_discover.c

11

1 files changed, 10 insertions, 1 deletions

diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index f47b4b281b14a…d7302c2052f91 100644
— a/drivers/scsi/libsas/sas_discover.c
+++ b/drivers/scsi/libsas/sas_discover.c

@@ -81,12 +81,21 @@ static int sas_get_port_device(struct asd_sas_port *port)

else

dev->dev_type = SAS_SATA_DEV;

dev->tproto = SAS_PROTOCOL_SATA;

- } else {

+ } else if (port->oob_mode == SAS_OOB_MODE) {

struct sas_identify_frame *id =

(struct sas_identify_frame *) dev->frame_rcvd;

dev->dev_type = id->dev_type;

dev->iproto = id->initiator_bits;

dev->tproto = id->target_bits;

+ } else {

+ /* If the oob mode is OOB_NOT_CONNECTED, the port is

+ * disconnected due to race with PHY down. We cannot

+ * continue to discover this port

+ */

+ sas_put_device(dev);

+ pr_warn("Port %016llx is disconnected when discovering\n",

+ SAS_ADDR(port->attached_sas_addr));

+ return -ENODEV;

}

sas_init_dev(dev);