syzbot


general protection fault in bit_putcs

Status: upstream: reported C repro on 2023/10/04 08:45
Subsystems: fbdev
[Documentation on labels]
Reported-by: syzbot+524697c54d6e7ec67cf2@syzkaller.appspotmail.com
First crash: 356d, last: 83d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [fbdev?] general protection fault in bit_putcs 0 (1) 2023/10/04 08:45
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 BUG: unable to handle kernel paging request in bit_putcs C done 4 86d 282d 3/3 fixed on 2024/04/03 01:55
linux-4.14 KASAN: global-out-of-bounds Read in bit_putcs C error 241 624d 1634d 0/1 upstream: reported C repro on 2019/12/07 16:26
linux-4.14 KASAN: slab-out-of-bounds Read in bit_putcs C error 95 625d 1638d 0/1 upstream: reported C repro on 2019/12/03 16:38
linux-4.19 KASAN: global-out-of-bounds Read in bit_putcs C done 214 1099d 1636d 1/1 fixed on 2021/06/24 08:01
linux-4.19 KASAN: slab-out-of-bounds Read in bit_putcs C inconclusive 138 1103d 1638d 0/1 upstream: reported C repro on 2019/12/03 12:47
Last patch testing requests (4)
Created Duration User Patch Repo Result
2024/05/15 18:22 2h25m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log
2024/03/06 11:09 27m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2023/12/27 10:37 17m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2023/10/18 09:45 17m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log

Sample crash report:
Unable to handle kernel paging request at virtual address dfff800000000040
KASAN: null-ptr-deref in range [0x0000000000000200-0x0000000000000207]
Mem abort info:
  ESR = 0x0000000096000005
  EC = 0x25: DABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x05: level 1 translation fault
Data abort info:
  ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000
  CM = 0, WnR = 0, TnD = 0, TagAccess = 0
  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[dfff800000000040] address between user and kernel address ranges
Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 6015 Comm: syz-executor865 Not tainted 6.6.0-rc3-syzkaller-g2e530aeb342b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __fb_pad_aligned_buffer include/linux/fb.h:629 [inline]
pc : bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
pc : bit_putcs+0x958/0xe30 drivers/video/fbdev/core/bitblit.c:185
lr : __fb_pad_aligned_buffer include/linux/fb.h:626 [inline]
lr : bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
lr : bit_putcs+0x93c/0xe30 drivers/video/fbdev/core/bitblit.c:185
sp : ffff800096a974a0
x29: ffff800096a976b0 x28: 0000000000000200 x27: ffff0000c8fb9010
x26: ffff0000c8fb9010 x25: 000000000000000f x24: dfff800000000000
x23: 0000000000000080 x22: 0000000000000000 x21: 0000000000000000
x20: ffff0000c0032440 x19: 0000000000000200 x18: ffff800096a96dc0
x17: ffff80008e19d000 x16: ffff80008a576f00 x15: 0000000000000009
x14: 1ffff00012d52ec1 x13: 0000000000000000 x12: 00000000ffffffff
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
x8 : 0000000000000040 x7 : 0000000000000000 x6 : 0000000000000007
x5 : 0000000000000000 x4 : 0000000000000008 x3 : ffff8000831e57e8
x2 : 0000000000000800 x1 : 0000000000000010 x0 : 0000000000000000
Call trace:
 __fb_pad_aligned_buffer include/linux/fb.h:629 [inline]
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
 bit_putcs+0x958/0xe30 drivers/video/fbdev/core/bitblit.c:185
 fbcon_putcs+0x318/0x4e8 drivers/video/fbdev/core/fbcon.c:1282
 do_update_region+0x42c/0x5f8 drivers/tty/vt/vt.c:623
 redraw_screen+0x82c/0xd54 drivers/tty/vt/vt.c:983
 fbcon_modechanged+0x9f4/0x1090 drivers/video/fbdev/core/fbcon.c:2703
 fbcon_update_vcs+0x3c/0x4c drivers/video/fbdev/core/fbcon.c:2748
 do_fb_ioctl+0xa68/0xd24 drivers/video/fbdev/core/fb_chrdev.c:92
 fb_ioctl+0xec/0x134 drivers/video/fbdev/core/fb_chrdev.c:169
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:871 [inline]
 __se_sys_ioctl fs/ioctl.c:857 [inline]
 __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:857
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x58/0x16c arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
Code: 51000679 aa1c03f3 d343fe68 12000a69 (38f86908) 
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	51000679 	sub	w25, w19, #0x1
   4:	aa1c03f3 	mov	x19, x28
   8:	d343fe68 	lsr	x8, x19, #3
   c:	12000a69 	and	w9, w19, #0x7
* 10:	38f86908 	ldrsb	w8, [x8, x24] <-- trapping instruction

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/10/04 08:45 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 2e530aeb342b 65faba36 .config console log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in bit_putcs
2023/09/19 10:18 upstream 2cf0f7156238 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root general protection fault in bit_putcs
2023/06/25 01:32 upstream a92b7d26c743 09ffe269 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root general protection fault in bit_putcs
2023/06/07 10:52 upstream a4d7d7011219 7086cdb9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root general protection fault in bit_putcs
2023/12/31 05:06 linux-next 39676dfe5233 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in bit_putcs
* Struck through repros no longer work on HEAD.