[PATCH 4.9 088/116] [media] s5p-mfc: fix failure path of s5p_mfc_alloc_memdev()

From: Greg Kroah-Hartman
Date: Fri Jan 06 2017 - 17:32:52 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>

commit 3467c9a7e7f9209a9ecd8f9db65b04a323a13932 upstream.

s5p_mfc_alloc_memdev() function lacks proper releasing
of allocated device in case of reserved memory initialization
failure. This results in NULL pointer dereference:

[ 2.828457] Unable to handle kernel NULL pointer dereference at virtual address 00000001
[ 2.835089] pgd = c0004000
[ 2.837752] [00000001] *pgd=00000000
[ 2.844696] Internal error: Oops: 5 [#1] PREEMPT SMP ARM
[ 2.848680] Modules linked in:
[ 2.851722] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.8.0-rc6-00002-gafa1b97 #878
[ 2.859357] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[ 2.865433] task: ef080000 task.stack: ef06c000
[ 2.869952] PC is at strcmp+0x0/0x30
[ 2.873508] LR is at platform_match+0x84/0xac
[ 2.877847] pc : [<c032621c>] lr : [<c03f65e8>] psr: 20000013
[ 2.877847] sp : ef06dea0 ip : 00000000 fp : 00000000
[ 2.889303] r10: 00000000 r9 : c0b34848 r8 : c0b1e968
[ 2.894511] r7 : 00000000 r6 : 00000001 r5 : c086e7fc r4 : eeb8e010
[ 2.901021] r3 : 0000006d r2 : 00000000 r1 : c086e7fc r0 : 00000001
[ 2.907533] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
[ 2.914649] Control: 10c5387d Table: 4000404a DAC: 00000051
[ 2.920378] Process swapper/0 (pid: 1, stack limit = 0xef06c210)
[ 2.926367] Stack: (0xef06dea0 to 0xef06e000)
[ 2.930711] dea0: eeb8e010 c0c2d91c c03f4a6c c03f4a8c 00000000 c0c2d91c c03f4a6c c03f2fc8
[ 2.938870] dec0: ef003274 ef10c4c0 c0c2d91c ef10cc80 c0c21270 c03f3fa4 c09c1be8 c0c2d91c
[ 2.947028] dee0: 00000006 c0c2d91c 00000006 c0b3483c c0c47000 c03f5314 c0c2d908 c0b5fed8
[ 2.955188] df00: 00000006 c010178c 60000013 c0a4ef14 00000000 c06feaa0 ef080000 60000013
[ 2.963347] df20: 00000000 c0c095c8 efffca76 c0816b8c 000000d5 c0134098 c0b34848 c09d6cdc
[ 2.971506] df40: c0a4de70 00000000 00000006 00000006 c0c09568 efffca40 c0b5fed8 00000006
[ 2.979665] df60: c0b3483c c0c47000 000000d5 c0b34848 c0b005a4 c0b00d84 00000006 00000006
[ 2.987824] df80: 00000000 c0b005a4 00000000 c06fb4d8 00000000 00000000 00000000 00000000
[ 2.995983] dfa0: 00000000 c06fb4e0 00000000 c01079b8 00000000 00000000 00000000 00000000
[ 3.004142] dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[ 3.012302] dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 ffffffff ffffffff
[ 3.020469] [<c032621c>] (strcmp) from [<c03f65e8>] (platform_match+0x84/0xac)
[ 3.027672] [<c03f65e8>] (platform_match) from [<c03f4a8c>] (__driver_attach+0x20/0xb0)
[ 3.035654] [<c03f4a8c>] (__driver_attach) from [<c03f2fc8>] (bus_for_each_dev+0x54/0x88)
[ 3.043812] [<c03f2fc8>] (bus_for_each_dev) from [<c03f3fa4>] (bus_add_driver+0xe8/0x1f4)
[ 3.051971] [<c03f3fa4>] (bus_add_driver) from [<c03f5314>] (driver_register+0x78/0xf4)
[ 3.059958] [<c03f5314>] (driver_register) from [<c010178c>] (do_one_initcall+0x3c/0x16c)
[ 3.068123] [<c010178c>] (do_one_initcall) from [<c0b00d84>] (kernel_init_freeable+0x120/0x1ec)
[ 3.076802] [<c0b00d84>] (kernel_init_freeable) from [<c06fb4e0>] (kernel_init+0x8/0x118)
[ 3.084958] [<c06fb4e0>] (kernel_init) from [<c01079b8>] (ret_from_fork+0x14/0x3c)
[ 3.092506] Code: 1afffffb e12fff1e e1a03000 eafffff7 (e4d03001)
[ 3.098618] ---[ end trace 511bf9d750810709 ]---
[ 3.103207] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b

This patch fixes this issue.

Fixes: c79667dd93b084fe412bcfe7fbf0ba43f7dec520 ("media: s5p-mfc: replace custom
reserved memory handling code with generic one")

Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/media/platform/s5p-mfc/s5p_mfc.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/media/platform/s5p-mfc/s5p_mfc.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c
@@ -1082,6 +1082,7 @@ static struct device *s5p_mfc_alloc_memd
idx);
if (ret == 0)
return child;
+ device_del(child);
}

put_device(child);