Alexey Dobriyan cf6e693212 loop: fix NULL dereference if mount fails ... Commit bb21488482 ("[PATCH] switch loop") started to pass NULL bdev to ioctl hook. Steps to reproduce: [boot with loop.max_part=1] [mount -o loop something so mount fails] BUG: unable to handle kernel NULL pointer dereference at 00000000000000b8 IP: [<ffffffff811486ee>] blkdev_ioctl+0x2e/0xa30 PGD 0 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC last sysfs file: /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:35/ACPI0003:00/power_supply/ACAD/online CPU 0 Modules linked in: zfs nvidia(P) [last unloaded: zfs] Pid: 15177, comm: mount Tainted: P 2.6.32-rc4-zfs #2 Satellite X200 RIP: 0010:[<ffffffff811486ee>] [<ffffffff811486ee>] blkdev_ioctl+0x2e/0xa30 RSP: 0018:ffff88003b3d5bb8 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 000000000000125f RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88003b3d5ce8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 00007ffffffff000 R13: 0000000000000000 R14: ffff880071cef280 R15: 00000000000200da FS: 00007fd77cfe7740(0000) GS:ffff880001600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00000000000000b8 CR3: 0000000001001000 CR4: 00000000000026f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process mount (pid: 15177, threadinfo ffff88003b3d4000, task ffff88007572f920) Stack: ffff88003b3d5c38 ffffffff812f95f5 ffff88007eeb6600 0000000000000000 <0> 0000000000000000 ffff88003b3d5c18 ffffffff811547d9 ffff88001bf11ef0 <0> 7fffffffffffffff ffff88001bf11ee8 ffff88001bf11ef0 0000000000000000 Call Trace: [<ffffffff812f95f5>] ? schedule_timeout+0x1f5/0x250 [<ffffffff811547d9>] ? rb_insert_color+0x109/0x140 [<ffffffff812fb754>] ? _spin_unlock_irq+0x14/0x40 [<ffffffff812f84c6>] ? wait_for_common+0x66/0x170 [<ffffffff8105a280>] ? default_wake_function+0x0/0x10 [<ffffffff810f8258>] ioctl_by_bdev+0x38/0x50 [<ffffffff811d2481>] loop_clr_fd+0x1e1/0x210 [<ffffffff811d2522>] lo_release+0x72/0x80 [<ffffffff810f934c>] __blkdev_put+0x1ac/0x1d0 [<ffffffff810f937b>] blkdev_put+0xb/0x10 [<ffffffff810f93b9>] blkdev_close+0x39/0x60 [<ffffffff810ccef3>] __fput+0xd3/0x230 [<ffffffff810cd06d>] fput+0x1d/0x30 [<ffffffff810c9680>] filp_close+0x50/0x80 [<ffffffff81061f11>] put_files_struct+0x81/0x100 [<ffffffff81061fde>] exit_files+0x4e/0x60 [<ffffffff81063ec5>] do_exit+0x6b5/0x730 [<ffffffff8107b279>] ? up_read+0x9/0x10 [<ffffffff8104c86e>] ? do_page_fault+0x18e/0x2a0 [<ffffffff81063f81>] do_group_exit+0x41/0xc0 [<ffffffff81064012>] sys_exit_group+0x12/0x20 [<ffffffff81030deb>] system_call_fastpath+0x16/0x1b Code: f8 48 89 e5 48 81 ec 30 01 00 00 48 89 5d d8 4c 89 6d e8 4c 89 65 e0 4c 89 75 f0 4c 89 7d f8 48 89 bd e8 fe ff ff 49 89 cd 89 f3 <49> 8b 88 b8 00 00 00 81 fa 68 12 00 00 0f 84 57 05 00 00 0f 86 RIP [<ffffffff811486ee>] blkdev_ioctl+0x2e/0xa30 RSP <ffff88003b3d5bb8> CR2: 00000000000000b8 ---[ end trace c0b4d3c3118d1427 ]--- Fixing recursive fault but reboot is needed! Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2009-10-29 07:39:27 -07:00
..
accessibility
acpi	Merge branch 'misc' into release	2009-10-15 00:47:13 -04:00
amba
ata	sata_mv: Prevent PIO commands to be defered too long if traffic in progress.	2009-10-16 06:22:46 -04:00
atm	net: Make setsockopt() optlen be unsigned.	2009-09-30 16:12:20 -07:00
auxdisplay
base
block	loop: fix NULL dereference if mount fails	2009-10-29 07:39:27 -07:00
bluetooth
cdrom
char	move virtrng_remove to .devexit.text	2009-10-22 16:39:34 +10:30
clocksource
connector	connector: Fix incompatible pointer type warning	2009-10-06 01:39:51 -07:00
cpufreq
cpuidle
crypto
dca
dio
dma
edac	amd64_edac: fix DRAM base and limit extraction masks, v2	2009-10-16 18:51:22 +02:00
eisa
firewire	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6	2009-10-14 15:36:19 -07:00
firmware	iSCSI/iBFT: use proper address translation	2009-10-05 12:05:40 -07:00
gpio	const: constify remaining file_operations	2009-10-01 16:11:11 -07:00
gpu	Merge branch 'drm-intel-next' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel	2009-10-09 09:19:23 -07:00
hid	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid	2009-10-13 10:10:33 -07:00
hwmon	Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging	2009-10-11 11:23:33 -07:00
i2c	i2c: Hide probe errors caused by ACPI resource conflicts	2009-10-04 22:53:45 +02:00
ide	ahci / atiixp / pci quirks: rename AMD SB900 into Hudson-2	2009-10-16 06:21:20 -04:00
idle
ieee1394	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
ieee802154
infiniband	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
input	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2009-10-22 08:27:12 +09:00
isdn	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
leds	leds: leds-pca9532 - Drop unused module parameters	2009-10-04 22:53:43 +02:00
lguest	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
macintosh	powerpc/pmac: Fix issues with sleep on some powerbooks	2009-10-14 16:58:35 +11:00
mca
md	dm snapshot: allow chunk size to be less than page size	2009-10-16 23:18:22 +01:00
media	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
memstick
message	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
mfd	mfd: Fix twl4030 boot with twl4030 usb transceiver enabled	2009-10-12 15:19:23 +02:00
misc	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
mmc	omap_hsmmc: add missing probe handler hook	2009-10-29 07:39:25 -07:00
mtd	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
net	Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus	2009-10-23 07:35:16 +09:00
nubus
of
oprofile	oprofile: warn on freeing event buffer too early	2009-10-09 21:32:05 +02:00
parisc
parport
pci	ahci / atiixp / pci quirks: rename AMD SB900 into Hudson-2	2009-10-16 06:21:20 -04:00
pcmcia	Merge master.kernel.org:/home/rmk/linux-2.6-arm	2009-10-02 16:20:43 -07:00
platform	Merge branch 'misc' into release	2009-10-15 00:47:13 -04:00
pnp
power
pps
ps3
rapidio
regulator
rtc	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
s390	[S390] sclp_vt220 build fix	2009-10-14 12:43:54 +02:00
sbus
scsi	Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6	2009-10-11 11:12:33 -07:00
serial	tty, serial: Fix race and NULL check in uart_close()	2009-10-12 10:21:33 -07:00
sfi	SFI: remove __init from sfi_verify_table	2009-10-03 01:16:12 -04:00
sh
sn
spi	ARM: 5741/1: pl022: fix peripheral id for ST vendor	2009-10-05 17:55:55 +01:00
ssb
staging	Staging: rt2860sta: prevent a panic when disabling when associated	2009-10-14 14:14:40 -07:00
tc
telephony
thermal
uio	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
usb	USB: gadget: Fix EEM driver comments and VID/PID	2009-10-14 14:54:44 -07:00
uwb	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
video	Merge branch 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6	2009-10-08 12:01:01 -07:00
virtio	move virtballoon_remove to .devexit.text	2009-10-22 16:39:31 +10:30
vlynq
w1	ds2482: Discard obsolete detect method	2009-10-04 22:53:41 +02:00
watchdog	watchdog: Fix rio watchdog probe function	2009-10-14 01:18:26 -07:00
xen	headers: remove sched.h from poll.h	2009-10-04 15:05:10 -07:00
zorro
Kconfig
Makefile