Marcin Slusarz 2e4a75cdcb rtc: fix kernel panic on second use of SIGIO nofitication ... When userspace uses SIGIO notification and forgets to disable it before closing file descriptor, rtc->async_queue contains stale pointer to struct file. When user space enables again SIGIO notification in different process, kernel dereferences this (poisoned) pointer and crashes. So disable SIGIO notification on close. Kernel panic: (second run of qemu (requires echo 1024 > /sys/class/rtc/rtc0/max_user_freq)) general protection fault: 0000 [1] PREEMPT CPU 0 Modules linked in: af_packet snd_pcm_oss snd_mixer_oss snd_seq_oss snd_seq_midi_event snd_seq usbhid tuner tea5767 tda8290 tuner_xc2028 xc5000 tda9887 tuner_simple tuner_types mt20xx tea5761 tda9875 uhci_hcd ehci_hcd usbcore bttv snd_via82xx snd_ac97_codec ac97_bus snd_pcm snd_timer ir_common compat_ioctl32 snd_page_alloc videodev v4l1_compat snd_mpu401_uart snd_rawmidi v4l2_common videobuf_dma_sg videobuf_core snd_seq_device snd btcx_risc soundcore tveeprom i2c_viapro Pid: 5781, comm: qemu-system-x86 Not tainted 2.6.27-rc6 #363 RIP: 0010:[<ffffffff8024f891>] [<ffffffff8024f891>] __lock_acquire+0x3db/0x73f RSP: 0000:ffffffff80674cb8 EFLAGS: 00010002 RAX: ffff8800224c62f0 RBX: 0000000000000046 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8800224c62f0 RBP: ffffffff80674d08 R08: 0000000000000002 R09: 0000000000000001 R10: ffffffff80238941 R11: 0000000000000001 R12: 0000000000000000 R13: 6b6b6b6b6b6b6b6b R14: ffff88003a450080 R15: 0000000000000000 FS: 00007f98b69516f0(0000) GS:ffffffff80623200(0000) knlGS:00000000f7cc86d0 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000a87000 CR3: 0000000022598000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process qemu-system-x86 (pid: 5781, threadinfo ffff880028812000, task ffff88003a450080) Stack: ffffffff80674cf8 0000000180238440 0000000200000002 0000000000000000 ffff8800224c62f0 0000000000000046 0000000000000000 0000000000000002 0000000000000002 0000000000000000 ffffffff80674d68 ffffffff8024fc7a Call Trace: <IRQ> [<ffffffff8024fc7a>] lock_acquire+0x85/0xa9 [<ffffffff8029cb62>] ? send_sigio+0x2a/0x184 [<ffffffff80491d1f>] _read_lock+0x3e/0x4a [<ffffffff8029cb62>] ? send_sigio+0x2a/0x184 [<ffffffff8029cb62>] send_sigio+0x2a/0x184 [<ffffffff8024fb97>] ? __lock_acquire+0x6e1/0x73f [<ffffffff8029cd4d>] ? kill_fasync+0x2c/0x4e [<ffffffff8029cd10>] __kill_fasync+0x54/0x65 [<ffffffff8029cd5b>] kill_fasync+0x3a/0x4e [<ffffffff80402896>] rtc_update_irq+0x9c/0xa5 [<ffffffff80404640>] cmos_interrupt+0xae/0xc0 [<ffffffff8025d1c1>] handle_IRQ_event+0x25/0x5a [<ffffffff8025e5e4>] handle_edge_irq+0xdd/0x123 [<ffffffff8020da34>] do_IRQ+0xe4/0x144 [<ffffffff8020bad6>] ret_from_intr+0x0/0xf <EOI> [<ffffffff8026fdc2>] ? __alloc_pages_internal+0xe7/0x3ad [<ffffffff8033fe67>] ? clear_page_c+0x7/0x10 [<ffffffff8026fc10>] ? get_page_from_freelist+0x385/0x450 [<ffffffff8026fdc2>] ? __alloc_pages_internal+0xe7/0x3ad [<ffffffff80280aac>] ? anon_vma_prepare+0x2e/0xf6 [<ffffffff80279400>] ? handle_mm_fault+0x227/0x6a5 [<ffffffff80494716>] ? do_page_fault+0x494/0x83f [<ffffffff8049251d>] ? error_exit+0x0/0xa9 Code: cc 41 39 45 28 74 24 e8 5e 1d 0f 00 85 c0 0f 84 6a 03 00 00 83 3d 8f a9 aa 00 00 be 47 03 00 00 0f 84 6a 02 00 00 e9 53 03 00 00 <41> ff 85 38 01 00 00 45 8b be 90 06 00 00 41 83 ff 2f 76 24 e8 RIP [<ffffffff8024f891>] __lock_acquire+0x3db/0x73f RSP <ffffffff80674cb8> ---[ end trace 431877d860448760 ]--- Kernel panic - not syncing: Aiee, killing interrupt handler! Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com> Acked-by: Alessandro Zummo <alessandro.zummo@towertech.it> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2008-10-03 18:22:17 -07:00
..
class.c
hctosys.c
interface.c
Kconfig	Blackfin RTC Driver: BF561 not have on-chip RTC	2008-08-20 15:40:30 -07:00
Makefile
rtc-at32ap700x.c
rtc-at91rm9200.c
rtc-at91sam9.c
rtc-bfin.c	Blackfin RTC Driver: dont let RTC programming in bootloaders randomly cause ~5 second boot delays	2008-08-20 15:40:30 -07:00
rtc-cmos.c	rtc-cmos: wake again from S5	2008-09-02 19:21:40 -07:00
rtc-core.h
rtc-dev.c	rtc: fix kernel panic on second use of SIGIO nofitication	2008-10-03 18:22:17 -07:00
rtc-ds1216.c
rtc-ds1302.c
rtc-ds1305.c
rtc-ds1307.c
rtc-ds1374.c	rtc: rtc-ds1374: fix 'no irq' case handling	2008-08-20 15:40:32 -07:00
rtc-ds1511.c
rtc-ds1553.c
rtc-ds1672.c
rtc-ds1742.c
rtc-ep93xx.c
rtc-fm3130.c
rtc-isl1208.c	rtc-isl1208: fix double removal of a sysfs entry	2008-08-12 16:07:28 -07:00
rtc-lib.c	rtc_time_to_tm: fix signed/unsigned arithmetic	2008-09-02 19:21:40 -07:00
rtc-m41t80.c
rtc-m41t94.c
rtc-m48t59.c
rtc-m48t86.c
rtc-max6900.c
rtc-max6902.c	removed unused #include <linux/version.h>'s	2008-08-23 12:14:12 -07:00
rtc-omap.c
rtc-pcf8563.c
rtc-pcf8583.c
rtc-pl030.c
rtc-pl031.c
rtc-ppc.c
rtc-proc.c
rtc-r9701.c	removed unused #include <linux/version.h>'s	2008-08-23 12:14:12 -07:00
rtc-rs5c313.c
rtc-rs5c348.c
rtc-rs5c372.c
rtc-s3c.c
rtc-s35390a.c
rtc-sa1100.c
rtc-sh.c
rtc-stk17ta8.c
rtc-sysfs.c
rtc-test.c
rtc-v3020.c
rtc-vr41xx.c
rtc-x1205.c