From: Arnd Bergmann <arnd@arndb.de> To: Dmitry Vyukov <dvyukov@google.com> Cc: "Russell King - ARM Linux admin" <linux@armlinux.org.uk>, syzbot <syzbot+0b06ef9b44d00d600183@syzkaller.appspotmail.com>, "Linus Walleij" <linus.walleij@linaro.org>, "Linux ARM" <linux-arm-kernel@lists.infradead.org>, "Andrew Morton" <akpm@linux-foundation.org>, LKML <linux-kernel@vger.kernel.org>, Linux-MM <linux-mm@kvack.org>, syzkaller-bugs <syzkaller-bugs@googlegroups.com>, "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de> Subject: Re: [syzbot] kernel panic: corrupted stack end in openat Date: Tue, 16 Mar 2021 17:28:24 +0100 [thread overview] Message-ID: <CAK8P3a3+hfb2so28xH4cJ_t8mf3H5U0oQJeNOWUAk5dOiQSdTw@mail.gmail.com> (raw) In-Reply-To: <CACT4Y+a0UxqLCYY8P2qNcS_19LmesXMJf=+DaCOBFVZyS0DkWQ@mail.gmail.com> On Tue, Mar 16, 2021 at 5:13 PM Dmitry Vyukov <dvyukov@google.com> wrote: > > On Tue, Mar 16, 2021 at 5:03 PM Arnd Bergmann <arnd@arndb.de> wrote: > > > > On Tue, Mar 16, 2021 at 4:51 PM Russell King - ARM Linux admin > > <linux@armlinux.org.uk> wrote: > > > On Tue, Mar 16, 2021 at 04:44:45PM +0100, Arnd Bergmann wrote: > > > > On Tue, Mar 16, 2021 at 11:17 AM Dmitry Vyukov <dvyukov@google.com> wrote: > > > > > The compiler is gcc version 10.2.1 20210110 (Debian 10.2.1-6) > > > > > > > > Ok, building with Ubuntu 10.2.1-1ubuntu1 20201207 locally, that's > > > > the closest I have installed, and I think the Debian and Ubuntu versions > > > > are generally quite close in case of gcc since they are maintained by > > > > the same packagers. > > > > > > ... which shouldn't be a problem - that's just over 1/4 of the stack > > > space. Could it be the syzbot's gcc is doing something weird and > > > inflating the stack frames? > > > > It's possible, I think that's really unlikely given that it's just Debian's > > gcc, which is as close to mainline as the version I was using. > > > > Uwe's DEBUG_STACKOVERFLOW patch from a while ago might > > help if this was the problem though: > > https://lore.kernel.org/linux-arm-kernel/20200108082913.29710-1-u.kleine-koenig@pengutronix.de/ > > > > My best guess is something going wrong in the interrupt > > that triggered the preempt_schedule() which ended up calling > > task_stack_end_corrupted() in schedule_debug(), as you suggested > > earlier. > > FWIW I see slightly larger frames with the config: > > 073ab64 <ima_calc_field_array_hash_tfm>: > 8073ab64: e1a0c00d mov ip, sp > 8073ab68: e92ddff0 push {r4, r5, r6, r7, r8, r9, sl, > fp, ip, lr, pc} > 8073ab6c: e24cb004 sub fp, ip, #4 > 8073ab70: e24ddfa7 sub sp, sp, #668 ; 0x29c Yes, this is the one that the compiler complained about when warning for stack over 600 bytes. It's not called in this call chain though. > page_alloc can also do reclaim, I had the impression that reclaim can > be quite heavy-weight in all respects. Yes, that is another possibility. What writable file systems or swap do you normally have mounted that it could be writing to, and on what storage device? Arnd
WARNING: multiple messages have this Message-ID (diff)
From: Arnd Bergmann <arnd@arndb.de> To: Dmitry Vyukov <dvyukov@google.com> Cc: "Russell King - ARM Linux admin" <linux@armlinux.org.uk>, syzbot <syzbot+0b06ef9b44d00d600183@syzkaller.appspotmail.com>, "Linus Walleij" <linus.walleij@linaro.org>, "Linux ARM" <linux-arm-kernel@lists.infradead.org>, "Andrew Morton" <akpm@linux-foundation.org>, LKML <linux-kernel@vger.kernel.org>, Linux-MM <linux-mm@kvack.org>, syzkaller-bugs <syzkaller-bugs@googlegroups.com>, "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de> Subject: Re: [syzbot] kernel panic: corrupted stack end in openat Date: Tue, 16 Mar 2021 17:28:24 +0100 [thread overview] Message-ID: <CAK8P3a3+hfb2so28xH4cJ_t8mf3H5U0oQJeNOWUAk5dOiQSdTw@mail.gmail.com> (raw) In-Reply-To: <CACT4Y+a0UxqLCYY8P2qNcS_19LmesXMJf=+DaCOBFVZyS0DkWQ@mail.gmail.com> On Tue, Mar 16, 2021 at 5:13 PM Dmitry Vyukov <dvyukov@google.com> wrote: > > On Tue, Mar 16, 2021 at 5:03 PM Arnd Bergmann <arnd@arndb.de> wrote: > > > > On Tue, Mar 16, 2021 at 4:51 PM Russell King - ARM Linux admin > > <linux@armlinux.org.uk> wrote: > > > On Tue, Mar 16, 2021 at 04:44:45PM +0100, Arnd Bergmann wrote: > > > > On Tue, Mar 16, 2021 at 11:17 AM Dmitry Vyukov <dvyukov@google.com> wrote: > > > > > The compiler is gcc version 10.2.1 20210110 (Debian 10.2.1-6) > > > > > > > > Ok, building with Ubuntu 10.2.1-1ubuntu1 20201207 locally, that's > > > > the closest I have installed, and I think the Debian and Ubuntu versions > > > > are generally quite close in case of gcc since they are maintained by > > > > the same packagers. > > > > > > ... which shouldn't be a problem - that's just over 1/4 of the stack > > > space. Could it be the syzbot's gcc is doing something weird and > > > inflating the stack frames? > > > > It's possible, I think that's really unlikely given that it's just Debian's > > gcc, which is as close to mainline as the version I was using. > > > > Uwe's DEBUG_STACKOVERFLOW patch from a while ago might > > help if this was the problem though: > > https://lore.kernel.org/linux-arm-kernel/20200108082913.29710-1-u.kleine-koenig@pengutronix.de/ > > > > My best guess is something going wrong in the interrupt > > that triggered the preempt_schedule() which ended up calling > > task_stack_end_corrupted() in schedule_debug(), as you suggested > > earlier. > > FWIW I see slightly larger frames with the config: > > 073ab64 <ima_calc_field_array_hash_tfm>: > 8073ab64: e1a0c00d mov ip, sp > 8073ab68: e92ddff0 push {r4, r5, r6, r7, r8, r9, sl, > fp, ip, lr, pc} > 8073ab6c: e24cb004 sub fp, ip, #4 > 8073ab70: e24ddfa7 sub sp, sp, #668 ; 0x29c Yes, this is the one that the compiler complained about when warning for stack over 600 bytes. It's not called in this call chain though. > page_alloc can also do reclaim, I had the impression that reclaim can > be quite heavy-weight in all respects. Yes, that is another possibility. What writable file systems or swap do you normally have mounted that it could be writing to, and on what storage device? Arnd _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-03-16 16:29 UTC|newest] Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-03-16 7:18 [syzbot] kernel panic: corrupted stack end in openat syzbot 2021-03-16 7:18 ` syzbot 2021-03-16 7:59 ` Dmitry Vyukov 2021-03-16 7:59 ` Dmitry Vyukov 2021-03-16 7:59 ` Dmitry Vyukov 2021-03-16 9:24 ` Russell King - ARM Linux admin 2021-03-16 9:24 ` Russell King - ARM Linux admin 2021-03-16 9:51 ` Dmitry Vyukov 2021-03-16 9:51 ` Dmitry Vyukov 2021-03-16 9:51 ` Dmitry Vyukov 2021-03-16 10:02 ` Arnd Bergmann 2021-03-16 10:02 ` Arnd Bergmann 2021-03-16 10:02 ` Arnd Bergmann 2021-03-16 10:17 ` Dmitry Vyukov 2021-03-16 10:17 ` Dmitry Vyukov 2021-03-16 10:17 ` Dmitry Vyukov 2021-03-16 15:44 ` Arnd Bergmann 2021-03-16 15:44 ` Arnd Bergmann 2021-03-16 15:44 ` Arnd Bergmann 2021-03-16 15:51 ` Russell King - ARM Linux admin 2021-03-16 15:51 ` Russell King - ARM Linux admin 2021-03-16 16:03 ` Dmitry Vyukov 2021-03-16 16:03 ` Dmitry Vyukov 2021-03-16 16:03 ` Dmitry Vyukov 2021-03-16 16:03 ` Arnd Bergmann 2021-03-16 16:03 ` Arnd Bergmann 2021-03-16 16:13 ` Dmitry Vyukov 2021-03-16 16:13 ` Dmitry Vyukov 2021-03-16 16:28 ` Arnd Bergmann [this message] 2021-03-16 16:28 ` Arnd Bergmann 2021-03-17 7:47 ` Dmitry Vyukov 2021-03-17 7:47 ` Dmitry Vyukov 2021-03-17 8:31 ` Arnd Bergmann 2021-03-17 8:31 ` Arnd Bergmann 2021-03-17 8:50 ` Dmitry Vyukov 2021-03-17 8:50 ` Dmitry Vyukov 2021-03-16 10:37 ` Ard Biesheuvel 2021-03-16 10:37 ` Ard Biesheuvel 2021-03-16 10:37 ` Ard Biesheuvel
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