================================================================== BUG: KASAN: vmalloc-out-of-bounds in fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline] BUG: KASAN: vmalloc-out-of-bounds in fb_bitmap_2ppw drivers/video/fbdev/core/fb_imageblit.h:364 [inline] BUG: KASAN: vmalloc-out-of-bounds in fb_bitmap_imageblit drivers/video/fbdev/core/fb_imageblit.h:462 [inline] BUG: KASAN: vmalloc-out-of-bounds in fb_imageblit drivers/video/fbdev/core/fb_imageblit.h:492 [inline] BUG: KASAN: vmalloc-out-of-bounds in sys_imageblit+0xc28/0x1758 drivers/video/fbdev/core/sysimgblt.c:24 Write of size 8 at addr ffff800093c79fc0 by task syz.3.1242/9550 CPU: 0 UID: 0 PID: 9550 Comm: syz.3.1242 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026 dump_backtrace(regs = 0000000000000000 tsk = 0000000000000000) Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_address_description+0xb0/0x238 mm/kasan/report.c:378 print_report+0x68/0x84 mm/kasan/report.c:482 kasan_report+0x8c/0xc4 mm/kasan/report.c:595 __asan_report_store8_noabort+0x20/0x2c mm/kasan/report_generic.c:386 fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline] fb_bitmap_2ppw drivers/video/fbdev/core/fb_imageblit.h:364 [inline] fb_bitmap_imageblit drivers/video/fbdev/core/fb_imageblit.h:462 [inline] fb_imageblit drivers/video/fbdev/core/fb_imageblit.h:492 [inline] sys_imageblit+0xc28/0x1758 drivers/video/fbdev/core/sysimgblt.c:24 drm_fbdev_shmem_defio_imageblit+0x38/0x144 drivers/gpu/drm/drm_fbdev_shmem.c:39 cw_putcs_aligned drivers/video/fbdev/core/fbcon_cw.c:111 [inline] cw_putcs+0x69c/0x8bc drivers/video/fbdev/core/fbcon_cw.c:159 fbcon_putcs+0x258/0x390 drivers/video/fbdev/core/fbcon.c:1399 do_update_region+0x31c/0x3c8 drivers/tty/vt/vt.c:656 redraw_screen+0x388/0x51c drivers/tty/vt/vt.c:1008 vc_do_resize+0x884/0xbbc drivers/tty/vt/vt.c:1309 __vc_resize+0x60/0x74 drivers/tty/vt/vt.c:1331 vt_resizex+0x318/0x4b0 drivers/tty/vt/vt_ioctl.c:715 vt_ioctl+0x734/0x1d4c drivers/tty/vt/vt_ioctl.c:927 tty_ioctl+0x828/0xcb0 drivers/tty/tty_io.c:2765 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __arm64_sys_ioctl+0x154/0x1cc fs/ioctl.c:583 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x60/0x1d8 arch/arm64/kernel/entry-common.c:796 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:815 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:606 The buggy address belongs to a vmalloc virtual mapping Memory state around the buggy address: ffff800093c79e80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffff800093c79f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 >ffff800093c79f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffff800093c7a000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffff800093c7a080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ================================================================== Unable to handle kernel paging request at virtual address ffff800093c79fc0 KASAN: probably user-memory-access in range [0x000000049e3cfe00-0x000000049e3cfe07] Mem abort info: ESR = 0x0000000096000047 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x07: level 3 translation fault Data abort info: ISV = 0, ISS = 0x00000047, ISS2 = 0x00000000 CM = 0, WnR = 1, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0 swapper pgtable: 4k pages, 48-bit VAs, pgdp=000000021af81000 [ffff800093c79fc0] pgd=0000000000000000, p4d=1000000221295003, pud=1000000221296003, pmd=1000000106f10403, pte=0000000000000000 Internal error: Oops: 0000000096000047 [#1] SMP Modules linked in: CPU: 0 UID: 0 PID: 9550 Comm: syz.3.1242 Tainted: G B L syzkaller #0 PREEMPT Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026 pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline] pc : fb_bitmap_2ppw drivers/video/fbdev/core/fb_imageblit.h:364 [inline] pc : fb_bitmap_imageblit drivers/video/fbdev/core/fb_imageblit.h:462 [inline] pc : fb_imageblit drivers/video/fbdev/core/fb_imageblit.h:492 [inline] pc : sys_imageblit+0xc30/0x1758 drivers/video/fbdev/core/sysimgblt.c:24 lr : fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline] lr : fb_bitmap_2ppw drivers/video/fbdev/core/fb_imageblit.h:364 [inline] lr : fb_bitmap_imageblit drivers/video/fbdev/core/fb_imageblit.h:462 [inline] lr : fb_imageblit drivers/video/fbdev/core/fb_imageblit.h:492 [inline] lr : sys_imageblit+0xc28/0x1758 drivers/video/fbdev/core/sysimgblt.c:24 sp : ffff8000962a73a0 x29: ffff8000962a7420 x28: dfff800000000000 x27: ffff800093c78ff8 x26: ffff800093c79fc0 x25: ffff0000c6848600 x24: 0000000000000004 x23: 0000000000000000 x22: ffff800093c79fc0 x21: 0000000000000000 x20: ffff0000c6848601 x19: ffff8000962a73f8 x18: 1fffe00035bd4c28 x17: 3d3d3d3d3d3d3d3d x16: 3d3d3d3d3d3d3d3d x15: 3d3d3d3d3d3d3d3d x14: 00000000000f2431 x13: 0000000000000001 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000080000 x9 : 0000000000000000 x8 : ffff0000d7b68000 x7 : 0000000000000000 x6 : ffff800080483164 x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff8000802f394c x2 : 0000000000000000 x1 : ffff0000d7b68000 x0 : ffff800093c79fc0 dump_backtrace(regs = 0000000049cf1637 tsk = 0000000000000000) Call trace: fb_bitmap_2ppw drivers/video/fbdev/core/fb_imageblit.h:365 [inline] (P) fb_bitmap_imageblit drivers/video/fbdev/core/fb_imageblit.h:462 [inline] (P) fb_imageblit drivers/video/fbdev/core/fb_imageblit.h:492 [inline] (P) sys_imageblit+0xc30/0x1758 drivers/video/fbdev/core/sysimgblt.c:24 (P) drm_fbdev_shmem_defio_imageblit+0x38/0x144 drivers/gpu/drm/drm_fbdev_shmem.c:39 cw_putcs_aligned drivers/video/fbdev/core/fbcon_cw.c:111 [inline] cw_putcs+0x69c/0x8bc drivers/video/fbdev/core/fbcon_cw.c:159 fbcon_putcs+0x258/0x390 drivers/video/fbdev/core/fbcon.c:1399 do_update_region+0x31c/0x3c8 drivers/tty/vt/vt.c:656 redraw_screen+0x388/0x51c drivers/tty/vt/vt.c:1008 vc_do_resize+0x884/0xbbc drivers/tty/vt/vt.c:1309 __vc_resize+0x60/0x74 drivers/tty/vt/vt.c:1331 vt_resizex+0x318/0x4b0 drivers/tty/vt/vt_ioctl.c:715 vt_ioctl+0x734/0x1d4c drivers/tty/vt/vt_ioctl.c:927 tty_ioctl+0x828/0xcb0 drivers/tty/tty_io.c:2765 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __arm64_sys_ioctl+0x154/0x1cc fs/ioctl.c:583 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x60/0x1d8 arch/arm64/kernel/entry-common.c:796 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:815 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:606 Code: aa1a03e0 97b7aa5c aa1a03e0 d34416e9 (f8008415) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: aa1a03e0 mov x0, x26 4: 97b7aa5c bl 0xfffffffffedea974 8: aa1a03e0 mov x0, x26 c: d34416e9 ubfx x9, x23, #4, #2 * 10: f8008415 str x21, [x0], #8 <-- trapping instruction