From b16a2d872dbf38bcbb5a385a8113ce3efd91859d Mon Sep 17 00:00:00 2001 From: Shuah Khan Date: Tue, 28 Jun 2016 16:17:18 -0300 Subject: [PATCH] [media] s5p-mfc: fix null pointer deference in clk_core_enable() Fix null pointer deference in clk_core_enable() when driver unbind is run when there is an application has an active pipeline playing. s5p_mfc_release() gets called after s5p_mfc_final_pm() disables and does clk_put() and s5p_mfc_release() attempts to enable clock and runs into null pointer deference accessing invalid pointer. [ 4869.434709] Unable to handle kernel NULL pointer dereference at virtual addr0 [ 4869.441312] pgd = e91ac000 [ 4869.443996] [00000010] *pgd=ba4f7835 [ 4869.447552] Internal error: Oops: 17 [#1] PREEMPT SMP ARM [ 4869.452921] Modules linked in: cpufreq_userspace cpufreq_powersave cpufreq_ca [ 4869.471728] CPU: 4 PID: 2965 Comm: lt-gst-launch-1 Not tainted 4.7.0-rc2-nex0 [ 4869.481778] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 4869.487844] task: e91f1e00 ti: ed650000 task.ti: ed650000 [ 4869.493227] PC is at clk_core_enable+0x4c/0x98 [ 4869.497637] LR is at clk_core_enable+0x40/0x98 [ 4869.502056] pc : [] lr : [] psr: 60060093 [ 4869.502056] sp : ed651f18 ip : 00000000 fp : 002641b4 [ 4869.513493] r10: e9088c08 r9 : 00000008 r8 : ed676d68 [ 4869.518692] r7 : ee3ac000 r6 : bf16b3c0 r5 : a0060013 r4 : ee37a8c0 [ 4869.525191] r3 : 00000000 r2 : 00000001 r1 : 00000004 r0 : 00000000 [ 4869.531692] Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment noe [ 4869.538883] Control: 10c5387d Table: 691ac06a DAC: 00000051 [ 4869.544603] Process lt-gst-launch-1 (pid: 2965, stack limit = 0xed650210) [ 4869.551361] Stack: (0xed651f18 to 0xed652000) [ 4869.555694] 1f00: ee373 [ 4869.563841] 1f20: bf16b3c0 c055a0e0 ee3ac004 ed676c10 bf16b3c0 bf1558e0 e9080 [ 4869.571986] 1f40: 00000000 ee98a510 ee502e40 bf047344 e9088c00 ee986938 00004 [ 4869.580132] 1f60: 00000000 00000000 e91f2204 00000000 c0b4658c e91f1e00 c0100 [ 4869.588277] 1f80: 00000000 c0135c58 ed650000 c0107904 ed651fb0 00000006 c0104 [ 4869.596423] 1fa0: 00229500 b6581000 b6f7b544 c0107794 00000000 00000002 b6f90 [ 4869.604568] 1fc0: 00229500 b6581000 b6f7b544 00000006 0017b600 0002c038 00264 [ 4869.612714] 1fe0: 00000000 bee56ef0 00000000 b6d49612 00060030 00000006 00000 [ 4869.620865] [] (clk_core_enable) from [] (clk_enable+0x2) [ 4869.628509] [] (clk_enable) from [] (s5p_mfc_release+0x3) [ 4869.637111] [] (s5p_mfc_release [s5p_mfc]) from [] (v4l2) [ 4869.646706] [] (v4l2_release [videodev]) from [] (__fput) [ 4869.654745] [] (__fput) from [] (task_work_run+0x94/0xc8) [ 4869.661852] [] (task_work_run) from [] (do_work_pending+) [ 4869.669735] [] (do_work_pending) from [] (slow_work_pend) [ 4869.677878] Code: ebffffef e3500000 18bd8070 e5943004 (e5933010) Signed-off-by: Shuah Khan Signed-off-by: Kamil Debski Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/s5p-mfc/s5p_mfc_pm.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c b/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c index 9f7522104333..930dc2dddae6 100644 --- a/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c +++ b/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c @@ -77,8 +77,10 @@ int s5p_mfc_init_pm(struct s5p_mfc_dev *dev) err_s_clk: clk_put(pm->clock); + pm->clock = NULL; err_p_ip_clk: clk_put(pm->clock_gate); + pm->clock_gate = NULL; err_g_ip_clk: return ret; } @@ -89,9 +91,11 @@ void s5p_mfc_final_pm(struct s5p_mfc_dev *dev) pm->clock) { clk_disable_unprepare(pm->clock); clk_put(pm->clock); + pm->clock = NULL; } clk_unprepare(pm->clock_gate); clk_put(pm->clock_gate); + pm->clock_gate = NULL; #ifdef CONFIG_PM pm_runtime_disable(pm->device); #endif @@ -99,12 +103,13 @@ void s5p_mfc_final_pm(struct s5p_mfc_dev *dev) int s5p_mfc_clock_on(void) { - int ret; + int ret = 0; #ifdef CLK_DEBUG atomic_inc(&clk_ref); mfc_debug(3, "+ %d\n", atomic_read(&clk_ref)); #endif - ret = clk_enable(pm->clock_gate); + if (!IS_ERR_OR_NULL(pm->clock_gate)) + ret = clk_enable(pm->clock_gate); return ret; } @@ -114,7 +119,8 @@ void s5p_mfc_clock_off(void) atomic_dec(&clk_ref); mfc_debug(3, "- %d\n", atomic_read(&clk_ref)); #endif - clk_disable(pm->clock_gate); + if (!IS_ERR_OR_NULL(pm->clock_gate)) + clk_disable(pm->clock_gate); } int s5p_mfc_power_on(void) -- 2.11.0