Comment 0 for bug 1689886

[Impact]
$ sudo ipmitool fru print 0
 Chassis Type : Rack Mount Chassis
 Chassis Part Number : ............
 Chassis Serial : ............
 Board Mfg Date : Wed Jan 4 14:18:00 2017
 Board Mfg : WIWYNN
 Board Product : REP Board
 Board Serial : 12345
 Board Part Number : ............
 Product Manufacturer : WIWYNN
 Product Name : REP
 Product Part Number : ..........
 Product Version : EVT
 Product Serial : ........................
 Product Asset Tag :
ubuntu@ubuntu:~/FRU$

ubuntu@ubuntu:~/FRU$ sudo ipmitool fru write 0 fru.bin
Fru Size : 1024 bytes
Size to Write : 256 bytes
[ 1815.412463] Unable to handle kernel NULL pointer dereference at virtual address 00000025
[ 1815.419668] pgd = ffff219ca2168000
[ 1815.422986] [00000025] *pgd=00000003ee08d003, *pud=00000003ee08e003, *pmd=0000000000000000
[ 1815.431225] Internal error: Oops: 96000004 [#1] SMP
[ 1815.436086] Modules linked in: ipmi_devintf nls_utf8 nls_cp437 vfat fat aes_ce_blk ablk_helper cryptd aes_ce_cipher ghash_ce sha2_ce efi_pstore sha1_ce sg efivars ipmi_ssif ipmi_msghandler cppc_cpufreq i2c_qup i2c_core efivarfs autofs4 ext4 crc16 jbd2 mbcache sd_mod ahci_platform libahci_platform libahci xhci_plat_hcd libata xhci_hcd scsi_mod usbcore msm_emac sdhci_acpi sdhci usb_common pinctrl_qdf2xxx
[ 1815.471677] CPU: 7 PID: 1950 Comm: kssif0042 Not tainted 4.7.0-2-generic #5~pdaw1.0+bandera.9-Ubuntu
[ 1815.480789] Hardware name: Default string Default string/Default string, BIOS 5.12 12/12/2012
[ 1815.489296] task: ffffedf1aa074380 ti: ffffedf1a7820000 task.ti: ffffedf1a7820000
[ 1815.496772] PC is at ipmi_ssif_thread+0x84/0x128 [ipmi_ssif]
[ 1815.502407] LR is at ipmi_ssif_thread+0x6c/0x128 [ipmi_ssif]
[ 1815.508046] pc : [<ffff219c9d09f614>] lr : [<ffff219c9d09f5fc>] pstate: 00400145
[ 1815.515424] sp : ffffedf1a7823de0
[ 1815.518723] x29: ffffedf1a7823de0 x28: 0000000000000000
[ 1815.524018] x27: 0000000000000000 x26: 0000000000000000
[ 1815.529313] x25: 0000000000000000 x24: 0000000000000000
[ 1815.534608] x23: ffffedeeb9dbba08 x22: ffff219c9d0a3000
[ 1815.539903] x21: ffff219c9d0a2420 x20: ffffedeeb9dbba00
[ 1815.545198] x19: ffffedeeb9dbb800 x18: 0000000000000014
[ 1815.550494] x17: 0000000000000000 x16: 0000000000000000
[ 1815.555789] x15: 0000000000000000 x14: 0000000000000000
[ 1815.561084] x13: 0000000000000000 x12: 071c71c71c71c71c
[ 1815.566379] x11: 00000000000000ba x10: 0000000000000960
[ 1815.571674] x9 : 0000000000000040 x8 : ffffedf1ad000028
[ 1815.576969] x7 : 0000000000000000 x6 : ffffedf1aa9f9600
[ 1815.582264] x5 : ffffedf1ad000000 x4 : 0000000000000000
[ 1815.587560] x3 : 0000000000000026 x2 : 0000000000000025
[ 1815.592855] x1 : 0000000000000007 x0 : ffffedf1aa2e4c00
[ 1815.598150]
[ 1815.599626] Process kssif0042 (pid: 1950, stack limit = 0xffffedf1a7820020)
[ 1815.606571] Stack: (0xffffedf1a7823de0 to 0xffffedf1a7824000)
[ 1815.612301] 3de0: ffffedf1a7823e20 ffff219ca122cb1c ffffedf1ab9d5800 ffff219ca20cdfa8
[ 1815.620113] 3e00: ffff219ca1aa2ee8 ffffedeeb9dbb800 ffff219c9d09f590 ffffedeeb9dbb800
[ 1815.627925] 3e20: 0000000000000000 ffff219ca11c4f10 ffff219ca122ca30 ffffedf1ab9d5800
[ 1815.635737] 3e40: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 1815.643550] 3e60: 0000000000000000 ffff219ca12399a8 ffffedeeb9dbb800 ffffedf100000000
[ 1815.651363] 3e80: 0000000000000000 ffffedf1a7823e88 ffffedf1a7823e88 0000000000000000
[ 1815.659175] 3ea0: 0000000000000000 ffffedf1a7823ea8 ffffedf1a7823ea8 cb88537fdc8ba500
[ 1815.666987] 3ec0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 1815.674800] 3ee0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 1815.682612] 3f00: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 1815.690425] 3f20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 1815.698237] 3f40: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 1815.706050] 3f60: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 1815.713862] 3f80: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 1815.721675] 3fa0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 1815.729487] 3fc0: 0000000000000000 0000000000000005 0000000000000000 0000000000000000
[ 1815.737300] 3fe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 1815.745112] Call trace:
[ 1815.747543] Exception stack(0xffffedf1a7823bf0 to 0xffffedf1a7823d20)
[ 1815.753966] 3be0: ffffedeeb9dbb800 0001000000000000
[ 1815.761779] 3c00: ffffedf1a7823de0 ffff219c9d09f614 0000000000400145 ffff219c9d0067c0
[ 1815.769592] 3c20: ffffedf1a5a59840 0000000000000005 0000000000000000 0000000000000042
[ 1815.777404] 3c40: 0000000000000006 0000000000000000 ffffedf1a7823db0 0000000000000000
[ 1815.785217] 3c60: 0000000000000000 ffff219ca1878a7c 7fffffffffffffff ffff219ca1875158
[ 1815.793029] 3c80: ffffedf1a7823d30 ffff002200000042 ffffedf1a7823cd0 ffff000000010042
[ 1815.800842] 3ca0: ffffedf1a7823ca8 cb88537fdc8ba500 ffffedf1aa2e4c00 0000000000000007
[ 1815.808654] 3cc0: 0000000000000025 0000000000000026 0000000000000000 ffffedf1ad000000
[ 1815.816467] 3ce0: ffffedf1aa9f9600 0000000000000000 ffffedf1ad000028 0000000000000040
[ 1815.824279] 3d00: 0000000000000960 00000000000000ba 071c71c71c71c71c 0000000000000000
[ 1815.832094] [<ffff219c9d09f614>] ipmi_ssif_thread+0x84/0x128 [ipmi_ssif]
[ 1815.838781] [<ffff219ca122cb1c>] kthread+0xec/0x100
[ 1815.843639] [<ffff219ca11c4f10>] ret_from_fork+0x10/0x40
[ 1815.848933] Code: f9411a62 350002c0 91000443 f940f660 (39400042)
[ 1815.855021] ---[ end trace db5a5cd0dc6b9dc4 ]---
No data available

[Regression Potential]
The patch to fix this issue is to the ipmi_ssif driver, it will have potential impact on systems using ipmi_ssif for ipmi interface and supports FRU writes.

[Test]
Listed in the impact statement. Further test results will be posted to this bug as comments.

[Fix]
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/char/ipmi/ipmi_ssif.c?id=6de65fcfdb51835789b245203d1bfc8d14cb1e06