From 5993a663a96df53f14d9e71abc27bcbd442317df Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Fri, 23 Jan 2009 21:35:12 -0300 Subject: [PATCH] V4L/DVB (10305): videobuf-vmalloc: Fix: videobuf memory were never freed videobuf_vmalloc_free() is never freeing the video buffer memory. Due to that, after multiple open/closes, user can suffer a panic: Kernel BUG at mm/slab.c:2650 invalid opcode: 0000 [1] SMP last sysfs file: /class/video4linux/video0/dev CPU 4 Modules linked in: vivi(U) videodev(U) v4l1_compat(U) v4l2_compat_ioctl32(U) videobuf_vmalloc(U) videobuf_core(U) ipv6 xfrm_nalgo autofs4 vmnet(U) vmblock(U) vmci(U) vmmon(U) ip_conntrack_netbios_ns ipt_REJECT xt_state ip_conntrack nfnetlink xt_tcpudp iptable_filter ip_tables x_tables cpufreq_ondemand dm_mirror dm_log dm_multipath scsi_dh dm_mod video backlight sbs i2c_ec button battery asus_acpi acpi_memhotplug ac lp testmgr_cipher testmgr aead crypto_blkcipher crypto_algapi crypto_api arc4 snd_hda_intel nvidia(PFU) snd_seq_dummy snd_seq_oss snd_seq_midi_event rt73usb crc_itu_t snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss tg3 sr_mod snd_pcm snd_timer snd_page_alloc snd_hwdep pcspkr rt2500usb cdrom rt2x00usb rt2x00lib libphy snd parport_pc soundcore shpchp serio_raw i2c_i801 i5400_edac parport ata_piix sg mac80211 edac_mc i2c_core cfg80211 ahci libata sd_mod scsi_mod ext3 jbd uhci_hcd ohci_hcd ehci_hcd Pid: 6215, comm: v4l-stress-buff Tainted: PF 2.6.18-118.el5 #1 RIP: 0010:[] [] cache_grow+0x1e/0x395 RSP: 0018:ffff810128a35d28 EFLAGS: 00010006 RAX: 0000000000000000 RBX: 00000000000080d0 RCX: 00000000ffffffff RDX: 0000000000000000 RSI: 00000000000080d0 RDI: ffff8101042d8340 RBP: ffff8101042ce5e0 R08: ffff81012fc1e8c0 R09: ffff8101042eac00 R10: 0000000000000000 R11: ffffffff882a5139 R12: ffff8101042d8340 R13: ffff8101042ce5c0 R14: 0000000000000000 R15: ffff8101042d8340 FS: 0000000000000000(0000) GS:ffff81012fc24d40(0063) knlGS:00000000f7f706c0 CS: 0010 DS: 002b ES: 002b CR0: 000000008005003b CR2: 00000000f7f9a000 CR3: 0000000117ad0000 CR4: 00000000000006e0 Process v4l-stress-buff (pid: 6215, threadinfo ffff810128a34000, task ffff810128fcb820) Stack: ffffc20012a39000 0000004415173ff8 ffff810000011c10 000280d200000000 0000000000000002 00000000ffffffff ffff8101042ce5e0 ffff81012fc1e8c0 ffff8101042ce5c0 000000000000000c ffff8101042d8340 ffffffff8005bdde Call Trace: [] cache_alloc_refill+0x136/0x186 [] kmem_cache_alloc_node+0x98/0xb2 [] __vmalloc_area_node+0x62/0x153 [] vmalloc_user+0x15/0x50 [] :videobuf_vmalloc:__videobuf_iolock+0xe6/0x155 [] :vivi:buffer_prepare+0xb9/0xe6 [] :videobuf_core:__videobuf_read_start+0xa2/0x10f [] :videobuf_core:videobuf_read_stream+0x9c/0x1f3 [] vfs_read+0xcb/0x171 [] sys_read+0x45/0x6e [] sysenter_do_call+0x1b/0x67 Code: 0f 0b 68 af 1e 2a 80 c2 5a 0a f6 c7 20 0f 85 53 03 00 00 89 RIP [] cache_grow+0x1e/0x395 RSP <0>Kernel panic - not syncing: Fatal exception Thanks to Douglas Schilling Landgraf for writing a stress tool for testing and to Robert Krakora to trace the code and discover the point where the bug were happening. Thanks also to Magnus Damm that provided us a fix for a similar bug on videobuf-dma-contig. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/videobuf-vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/video/videobuf-vmalloc.c b/drivers/media/video/videobuf-vmalloc.c index be65a2fb3976..30ae30f99ccc 100644 --- a/drivers/media/video/videobuf-vmalloc.c +++ b/drivers/media/video/videobuf-vmalloc.c @@ -425,7 +425,7 @@ void videobuf_vmalloc_free (struct videobuf_buffer *buf) So, it should free memory only if the memory were allocated for read() operation. */ - if ((buf->memory != V4L2_MEMORY_USERPTR) || (buf->baddr == 0)) + if ((buf->memory != V4L2_MEMORY_USERPTR) || buf->baddr) return; if (!mem) -- 2.30.2