From d2b903b4427e417a73863cef36ad0796ea6b7404 Mon Sep 17 00:00:00 2001 From: Sylwester Nawrocki Date: Mon, 29 Jul 2013 06:53:59 -0300 Subject: [PATCH] [media] exynos4-is: Fix entity unregistration on error path This patch corrects media entities unregistration order to make sure the fimc.N.capture and fimc-lite video nodes are unregistered with fimc->lock mutex held. This prevents races between video device open() and defered probing and NULL pointer dereference in open() callback as follows: [ 77.645000] Unable to handle kernel NULL pointer dereference at virtual address 00000290t [ 77.655000] pgd = ee7a8000 [ 77.660000] [00000290] *pgd=6e13c831, *pte=00000000, *ppte=00000000 [ 77.665000] Internal error: Oops: 17 [#1] PREEMPT SMP ARM [ 77.670000] Modules linked in: s5p_fimc ipv6 exynos_fimc_is exynos_fimc_lite s5p_csis v4l2_mem2mem videobuf2_dma_contig videobuf2_memops exynos4_is_common videobuf2_core [last unloaded: s5p_fimc] [ 77.685000] CPU: 0 PID : 2998 Comm: v4l_id Tainted: G W 3.10.0-next-20130709-00039-g39f491b-dirty #1548 [ 77.695000] task: ee084000 ti: ee46e000 task.ti: ee46e000 [ 77.700000] PC is at __mutex_lock_slowpath+0x54/0x368 [ 77.705000] LR is at __mutex_lock_slowpath+0x24/0x368 [ 77.710000] pc : [] lr : [] psr: 60000093 [ 77.710000] sp : ee46fd70 ip : 000008c8 fp : c054e34c [ 77.725000] r10: ee084000 r9 : 00000000 r8 : ee439480 [ 77.730000] r7 : ee46e000 r6 : 60000013 r5 : 00000290 r4 : 0000028c [ 77.735000] r3 : 00000000 r2 : 00000000 r1 : 20000093 r0 : 00000001 [ 77.740000] Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user [ 77.750000] Control: 10c5387d Table: 6e7a804a DAC: 00000015 [ 77.755000] Process v4l_id (pid: 2998, stack limit = 0xee46e238) [ 77.760000] Stack: (0xee46fd70 to 0xee470000) ... [ 77.935000] [] (__mutex_lock_slowpath+0x54/0x368) from [] (mutex_lock+0xc/0x24) [ 77.945000] [] (mutex_lock+0xc/0x24) from [] (fimc_lite_open+0x12c/0x2bc [exynos_fimc_lite]) [ 77.955000] [] (fimc_lite_open+0x12c/0x2bc [exynos_fimc_lite]) from [] (v4l2_open+0xa0/0xe0) [ 77.965000] [] (v4l2_open+0xa0/0xe0) from [] (chrdev_open+0x88/0x170) [ 77.975000] [] (chrdev_open+0x88/0x170) from [] (do_dentry_open.isra.14+0x1d8/0x258) [ 77.985000] [] (do_dentry_open.isra.14+0x1d8/0x258) from [] (finish_open+0x20/0x38) [ 77.995000] [] (finish_open+0x20/0x38) from [] (do_last.isra.43+0x538/0xb1c) [ 78.000000] [] (do_last.isra.43+0x538/0xb1c) from [] (path_openat+0xb4/0x5c4) [ 78.010000] [] (path_openat+0xb4/0x5c4) from [] (do_filp_open+0x2c/0x80) [ 78.020000] [] (do_filp_open+0x2c/0x80) from [] (do_sys_open+0xf4/0x1a8) [ 78.025000] [] (do_sys_open+0xf4/0x1a8) from [] (ret_fast_syscall+0x0/0x30) [ 78.035000] Code: 1a000093 e10f6000 f10c0080 e2845004 (e1953f9f) Reported-by: Andrzej Hajda Signed-off-by: Sylwester Nawrocki Signed-off-by: Kyungmin Park Signed-off-by: Mauro Carvalho Chehab Cc: stable@vger.kernel.org --- drivers/media/platform/exynos4-is/media-dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/platform/exynos4-is/media-dev.c b/drivers/media/platform/exynos4-is/media-dev.c index ef6642b3fab5..e327f455e0a5 100644 --- a/drivers/media/platform/exynos4-is/media-dev.c +++ b/drivers/media/platform/exynos4-is/media-dev.c @@ -1523,9 +1523,9 @@ static int fimc_md_probe(struct platform_device *pdev) err_unlock: mutex_unlock(&fmd->media_dev.graph_mutex); err_clk: - media_device_unregister(&fmd->media_dev); fimc_md_put_clocks(fmd); fimc_md_unregister_entities(fmd); + media_device_unregister(&fmd->media_dev); err_md: v4l2_device_unregister(&fmd->v4l2_dev); return ret; -- 2.30.2