On 7/3/23 06:30, Kees Cook wrote:
On Mon, Jul 03, 2023 at 05:53:48AM +0200, Mirsad Goran Todorovac wrote:On 7/3/23 05:26, Guenter Roeck wrote:On 7/2/23 20:20, Kees Cook wrote:On Mon, Jul 03, 2023 at 08:44:37AM +0700, Bagas Sanjaya wrote:On Sun, Jul 02, 2023 at 06:36:12PM +0200, Mirsad Goran Todorovac wrote:Hi, After new git pull the kernel in Torvalds tree with default debug config failed to boot with error that occurs prior to mounting filesystems, so there is no log safe for the screenshot(s) here: [1] https://domac.alu.unizg.hr/~mtodorov/linux/crashes/2023-07-02/ Bisect shows the first bad commit is 2d47c6956ab3 (v6.4-rc2-1-g2d47c6956ab3): # good: [98be618ad03010b1173fc3c35f6cbb4447ee2b07] Merge tag 'Smack-for-6.5' of https://github.com/cschaufler/smack-next git bisect good 98be618ad03010b1173fc3c35f6cbb4447ee2b07 # bad: [f4a0659f823e5a828ea2f45b4849ea8e2dd2984c] drm/i2c: tda998x: Replace all non-returning strlcpy with strscpy git bisect bad f4a0659f823e5a828ea2f45b4849ea8e2dd2984c . . . # bad: [2d47c6956ab3c8b580a59d7704aab3e2a4882b6c] ubsan: Tighten UBSAN_BOUNDS on GCC git bisect bad 2d47c6956ab3c8b580a59d7704aab3e2a4882b6c # first bad commit: [2d47c6956ab3c8b580a59d7704aab3e2a4882b6c] ubsan: Tighten UBSAN_BOUNDS on GCC The architecture is Ubuntu 22.04 with lshw and config give in the attachment.Can you show early kernel log (something like dmesg)? Anyway, I'm adding it to regzbot: #regzbot ^introduced: 2d47c6956ab3c8 #regzbot title: Linux kernel fails to boot due to UBSAN_BOUNDS tighteningI'm confused. Commit 2d47c6956ab3c8b580a59d7704aab3e2a4882b6c isn't in the v6.4 tree... it's only in Linus's ToT.In ToT: $ git describe 2d47c6956ab3 v6.4-rc2-1-g2d47c6956ab3 $ git describe --contains 2d47c6956ab3 next-20230616~2^2~51 $ git describe --contains --match 'v*' 2d47c6956ab3 fatal: cannot describe '2d47c6956ab3c8b580a59d7704aab3e2a4882b6c' "git describe" always shows the parent tree, which I guess was based on v6.4-rc2. GuenterAlso, the config you included does not show CONFIG_UBSAN_BOUNDS_STRICT as even being available, much less present. Something seems very wrong with this report... -KeesAnyway, I have double checked and linux-image-6.4.0-rc2-crash boots while linux-image-6.4.0-rc2-crash-00001-g2d47c6956ab3 freezes in early boot.I don't understand what tree you're testing. 2d47c6956ab3 is only in Linus's latest tree, which is not 6.4-rc2.
If you're testing Linus's tree, and you're bisecting to 2d47c6956ab3, I don't understand why the .config you sent doesn't include CONFIG_UBSAN_BOUNDS_STRICT (which was introduced by that commit) -- it should be visible whether or not it is selected.
Hi, Mr. Cook, I have cloned again from the Torvalds' tree, and rebuilt both kernels with the config attached. linux-image-6.4.0-rc2-crash2 again boots, and linux-image-6.4.0-rc2-crash2-00001-g2d47c6956ab3 crashes during the early boot. There is nothing from -00001-g2d47c6956ab3 kernel in the logs. It is this very config and vanilla Torvalds tree from git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Hope this helps. Best regards, Mirsad Todorovac
Of course, in the next boot dmesg appears overwritten ... I could provide only the first screen screenshots.Without CONFIG_UBSAN_TRAP, I would not expect anything other than a warning (i.e. boot would continue). The only other thing I can think of that seems related (the backtrace appears to show usb), might be this: https://lore.kernel.org/lkml/20230629190900.never.787-kees@xxxxxxxxxx/ which won't appears until after v6.5-rc1.The difference is only one commit. It is a bit strange so I am available for any additional diagnostics.Thanks! Can you send "grep UBSAN .config" output for the crashing kernel? Are you booting on an EFI-capable machine? If you could configure pstore to use the EFI-vars backend, you can capture the crash in EFI and pstorefs will show it after the next boot. (If you're using systemd, this all may already be happening -- check /var/lib/systemd/pstore/ or see[1] for more details.) -Kees [1] https://www.freedesktop.org/software/systemd/man/systemd-pstore.service.html
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