| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20090516154912.a0efc677.akpm@linux-foundation.org> Date: Sat, 16 May 2009 15:49:12 -0700 From: Andrew Morton <akpm@...ux-foundation.org> To: Alessandro Zummo <alessandro.zummo@...ertech.it> Cc: rtc-linux@...glegroups.com, mingo@...e.hu, Ozan Çağlayan <ozan@...dus.org.tr>, David Brownell <david-b@...bell.net>, "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, Kay Sievers <kay.sievers@...y.org>, Greg KH <greg@...ah.com>, Tejun Heo <tj@...nel.org> Subject: Re: [rtc-linux] Re: [BUG 2.6.30_rc5] Null pointer dereference in rtc-cmos driver On Fri, 15 May 2009 21:01:34 +0200 Alessandro Zummo <alessandro.zummo@...ertech.it> wrote: > On Fri, 15 May 2009 19:40:56 +0200 > Ingo Molnar <mingo@...e.hu> wrote: > > more Cc:s > c'mon guys, it isn't that hard. > > ... > > > > [ 10.428691] Error: Driver 'rtc_cmos' is already registered, aborting... This should fix the symptoms: From: Andrew Morton <akpm@...ux-foundation.org> Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13326 Prevents a null-pointer deref under the above-described circumstances. pnp_unregister_driver() shouldn't oops the kernel either - that's a different bug. Reported-by: <ozan@...dus.org.tr> Cc: Alessandro Zummo <alessandro.zummo@...ertech.it> Cc: Ingo Molnar <mingo@...e.hu> Cc: David Brownell <david-b@...bell.net> Cc: Bjorn Helgaas <bjorn.helgaas@...com> Signed-off-by: Andrew Morton <akpm@...ux-foundation.org> --- drivers/rtc/rtc-cmos.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff -puN drivers/rtc/rtc-cmos.c~drivers-rtc-rtc-cmosc-cmos_init-dont-ignore-pnp_register_driver-return-value drivers/rtc/rtc-cmos.c --- a/drivers/rtc/rtc-cmos.c~drivers-rtc-rtc-cmosc-cmos_init-dont-ignore-pnp_register_driver-return-value +++ a/drivers/rtc/rtc-cmos.c @@ -1179,7 +1179,9 @@ static int __init cmos_init(void) int retval = 0; #ifdef CONFIG_PNP - pnp_register_driver(&cmos_pnp_driver); + retval = pnp_register_driver(&cmos_pnp_driver); + if (retval < 0) + return retval; #endif if (!cmos_rtc.dev) _ Can someone please test it? > > > [ 10.428728] BUG: unable to handle kernel NULL pointer dereference at 00000018 > > > [ 10.432460] IP: [<c01e16ba>] sysfs_remove_file+0x1/0xf > > > [ 10.459009] *pde = 00000000 > > > [ 10.459009] Oops: 0000 [#1] SMP > > > [ 10.459009] last sysfs file: /sys/devices/pci0000:00/0000:00:12.0/host2/target2:0:0/2:0:0:0/type > > > [ 10.459009] Modules linked in: rtc_cmos(+) sg ati_agp k8temp hwmon i2c_piix4 shpchp agpgart i2c_core mii brd sd_mod crc_t10dif sr_mod cdrom ata_generic pata_acpi ahci pata_atiixp libata scsi_mod > > > [ 10.459009] > > > [ 10.459009] Pid: 633, comm: modprobe Tainted: G W (2.6.30_rc5-116 #1) Unknow > > > [ 10.459009] EIP: 0060:[<c01e16ba>] EFLAGS: 00210282 CPU: 1 > > > [ 10.459009] EIP is at sysfs_remove_file+0x1/0xf > > > [ 10.459009] EAX: 00000000 EBX: f885a2ec ECX: c1e1a664 EDX: c054d1a0 > > > [ 10.459009] ESI: 00000000 EDI: 00000000 EBP: f6bcdf08 ESP: f6bcdf00 > > > [ 10.459009] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 > > > [ 10.459009] Process modprobe (pid: 633, ti=f6bcc000 task=f6a8d710 task.ti=f6bcc000) > > > [ 10.459009] Stack: > > > [ 10.459009] f6bcdf08 c03037e6 f6bcdf1c c0302809 00000000 f885a2ec 00000000 f6bcdf2c > > > [ 10.459009] c030367d ffffffed fffffffc f6bcdf34 c02dcf14 f6bcdf40 f885d038 f885a38c > > > [ 10.459009] f6bcdf9c c0101137 f885d000 00000000 f885a38c 00000001 00000000 c0536a04 > > > [ 10.459009] Call Trace: > > > [ 10.459009] [<c03037e6>] ? driver_remove_file+0xf/0x11 > > > [ 10.459009] [<c0302809>] ? bus_remove_driver+0x1a/0x89 > > > [ 10.459009] [<c030367d>] ? driver_unregister+0x2a/0x2e > > > [ 10.459009] [<c02dcf14>] ? pnp_unregister_driver+0xb/0xd > > > [ 10.459009] [<f885d038>] ? cmos_init+0x38/0x3d [rtc_cmos] > > > [ 10.459009] [<c0101137>] ? do_one_initcall+0x4a/0x115 > > > [ 10.459009] [<f885d000>] ? cmos_init+0x0/0x3d [rtc_cmos] > > > [ 10.459009] [<c0145a65>] ? __blocking_notifier_call_chain+0x40/0x4c > > > [ 10.459009] [<c01538d0>] ? sys_init_module+0x87/0x18b > > > [ 10.459009] [<c01031d4>] ? sysenter_do_call+0x12/0x28 > > > [ 10.459009] Code: 43 04 89 42 04 89 10 b8 08 9f 53 c0 c7 46 e8 00 01 10 00 c7 43 04 00 02 20 00 e8 1e 9e 1f 00 89 d8 e8 fa ba fb ff 5b 5e 5d c3 55 <8b> 40 18 8b 12 89 e5 e8 12 f5 ff ff 5d c3 55 85 c9 89 e5 57 89 > > > [ 10.459009] EIP: [<c01e16ba>] sysfs_remove_file+0x1/0xf SS:ESP 0068:f6bcdf00 But we have arguably multiple more bugs here. pnp_unregister_driver(unregistered-driver) shouldn't oops the kernel. Neither pnp_unregister_driver() nor driver_unregister() nor bus_remove_driver() nor driver_remove_file() nor sysfs_remove_file() detected this. Kay, Greg: there are already a pile of checks on that path, but it seems there's one missing. Could you please take a look and decide at the design level where this check should be occurring? Rafael, let's keep this one open even if the rtc-cmos fix repairs the proximate cause. Thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists