From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: From: Lars Poeschel To: Peter Robinson Cc: linux-watchdog@vger.kernel.org, linux-omap@vger.kernel.org, stable@vger.kernel.org, Guenter Roeck Subject: Re: [PATCH] watchdog: omap_wdt: fix null pointer dereference Date: Wed, 04 Nov 2015 11:31:02 +0100 Message-ID: <2593393.lungi1Qs6x@lem-wkst-02> In-Reply-To: <1446430820-29252-1-git-send-email-pbrobinson@gmail.com> References: <1446430820-29252-1-git-send-email-pbrobinson@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" List-ID: On Wednesday 04 November 2015 02:20:20, Peter Robinson wrote: > Fix issue from two patches overlapping causing a kernel oops > > [ 3569.297449] Unable to handle kernel NULL pointer dereference at virtual > address 00000088 [ 3569.306272] pgd = dc894000 > [ 3569.309287] [00000088] *pgd=00000000 > [ 3569.313104] Internal error: Oops: 5 [#1] SMP ARM > [ 3569.317986] Modules linked in: ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 > xt_conntrack ebtable_filter ebtable_nat ebtable_broute bridge stp llc > ebtables ip6table_security ip6table_raw ip6table_nat nf_conntrack_ipv6 > nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_filter ip6_tables > iptable_security iptable_raw iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 > nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle musb_dsps cppi41 musb_hdrc > phy_am335x udc_core phy_generic phy_am335x_control omap_sham omap_aes > omap_rng omap_hwspinlock omap_mailbox hwspinlock_core musb_am335x omap_wdt > at24 8250_omap leds_gpio cpufreq_dt smsc davinci_mdio mmc_block ti_cpsw > cpsw_common ptp pps_core cpsw_ale davinci_cpdma omap_hsmmc omap_dma > mmc_core i2c_dev [ 3569.386293] CPU: 0 PID: 1429 Comm: wdctl Not tainted > 4.3.0-0.rc7.git0.1.fc24.armv7hl #1 [ 3569.394740] Hardware name: Generic > AM33XX (Flattened Device Tree) [ 3569.401179] task: dbd11a00 ti: dbaac000 > task.ti: dbaac000 > [ 3569.406917] PC is at omap_wdt_get_timeleft+0xc/0x20 [omap_wdt] > [ 3569.413106] LR is at watchdog_ioctl+0x3cc/0x42c > [ 3569.417902] pc : [] lr : [] psr: 600f0013 > [ 3569.417902] sp : dbaadf18 ip : 00000003 fp : 7f5d3bbe > [ 3569.430014] r10: 00000000 r9 : 00000003 r8 : bef21ab8 > [ 3569.435535] r7 : dbbc0f7c r6 : dbbc0f18 r5 : bef21ab8 r4 : 00000000 > [ 3569.442427] r3 : 00000000 r2 : 00000000 r1 : 8004570a r0 : dbbc0f18 > [ 3569.449323] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment > none [ 3569.456858] Control: 10c5387d Table: 9c894019 DAC: 00000051 > [ 3569.462927] Process wdctl (pid: 1429, stack limit = 0xdbaac220) > [ 3569.469179] Stack: (0xdbaadf18 to 0xdbaae000) > [ 3569.473790] df00: > bef21ab8 dbf60e38 [ 3569.482441] df20: dc91b840 8004570a bef21ab8 c03988a4 > dbaadf48 dc854000 00000000 dd313850 [ 3569.491092] df40: ddf033b8 0000570a > dc91b80b dbaadf3c dbf60e38 00000020 c0df9250 c0df6c48 [ 3569.499741] df60: > dc91b840 8004570a 00000000 dc91b840 dc91b840 8004570a bef21ab8 00000003 [ > 3569.508389] df80: 00000000 c03989d4 bef21b74 7f5d3bad 00000003 00000036 > c020fcc4 dbaac000 [ 3569.517037] dfa0: 00000000 c020fb00 bef21b74 7f5d3bad > 00000003 8004570a bef21ab8 00000001 [ 3569.525685] dfc0: bef21b74 7f5d3bad > 00000003 00000036 00000001 00000000 7f5e4eb0 7f5d3bbe [ 3569.534334] dfe0: > 7f5e4f10 bef21a3c 7f5d0a54 b6e97e0c a00f0010 00000003 00000000 00000000 [ > 3569.543038] [] (omap_wdt_get_timeleft [omap_wdt]) from > [] (watchdog_ioctl+0x3cc/0x42c) [ 3569.553266] [] > (watchdog_ioctl) from [] (do_vfs_ioctl+0x5bc/0x698) [ > 3569.561648] [] (do_vfs_ioctl) from [] > (SyS_ioctl+0x54/0x7c) [ 3569.569400] [] (SyS_ioctl) from > [] (ret_fast_syscall+0x0/0x3c) [ 3569.577413] Code: e12fff1e > e52de004 e8bd4000 e5903060 (e5933088) [ 3569.584089] ---[ end trace > cec3039bd3ae610a ]--- > > Cc: # v4.2+ > Cc: Guenter Roeck > Cc: Lars Poeschel > Signed-off-by: Peter Robinson Peter, thank you for catching this one. Acked-by: Lars Poeschel > --- > drivers/watchdog/omap_wdt.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c > index d96bee0..6f17c93 100644 > --- a/drivers/watchdog/omap_wdt.c > +++ b/drivers/watchdog/omap_wdt.c > @@ -205,7 +205,7 @@ static int omap_wdt_set_timeout(struct watchdog_device > *wdog, > > static unsigned int omap_wdt_get_timeleft(struct watchdog_device *wdog) > { > - struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog); > + struct omap_wdt_dev *wdev = to_omap_wdt_dev(wdog); > void __iomem *base = wdev->base; > u32 value;