================================================================== 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 ffff8000936d9be0 by task kworker/u8:2/40 CPU: 1 UID: 0 PID: 40 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026 Workqueue: events_power_efficient fb_flashcursor 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 soft_cursor+0x534/0x6bc drivers/video/fbdev/core/softcursor.c:74 bit_cursor+0xaac/0x112c drivers/video/fbdev/core/bitblit.c:370 fb_flashcursor+0x268/0x398 drivers/video/fbdev/core/fbcon.c:423 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0x91c/0x1250 kernel/workqueue.c:3479 worker_thread+0x798/0xbd0 kernel/workqueue.c:3560 kthread+0x304/0x3d4 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:854 The buggy address belongs to a 1-page vmalloc region starting at 0xffff8000936d9000 allocated at ebt_register_table+0x1dc/0x9e4 net/bridge/netfilter/ebtables.c:1210 The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff000100000000 pfn:0x142445 flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000000 0000000000000000 dead000000000122 0000000000000000 raw: ffff000100000000 0000000000000000 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8000936d9a80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffff8000936d9b00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 >ffff8000936d9b80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ^ ffff8000936d9c00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 ffff8000936d9c80: 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 ffff8000936dabe0 KASAN: probably user-memory-access in range [0x000000049b6d5f00-0x000000049b6d5f07] 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=000000021b181000 [ffff8000936dabe0] pgd=0000000000000000, p4d=1000000221494003, pud=1000000221495003, pmd=1000000106d65403, pte=0000000000000000 Internal error: Oops: 0000000096000047 [#1] SMP Modules linked in: CPU: 1 UID: 0 PID: 40 Comm: kworker/u8:2 Tainted: G B syzkaller #0 PREEMPT Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026 Workqueue: events_power_efficient fb_flashcursor pstate: 03400005 (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 : ffff80008efc7790 x29: ffff80008efc7810 x28: dfff800000000000 x27: ffff8000936d9bf8 x26: ffff8000936dabe0 x25: ffff0000c6520e81 x24: 0000000000000004 x23: 0000000000000000 x22: ffff8000936dabe0 x21: 0000000000000000 x20: ffff0000c6520e82 x19: ffff80008efc77e8 x18: 1fffe00035bd9828 x17: 3d3d3d3d3d3d3d3d x16: 3d3d3d3d3d3d3d3d x15: 3d3d3d3d3d3d3d3d x14: 0000000000008285 x13: 0000000000000001 x12: 0000000000000000 x11: 0000000000000000 x10: ffff700011451b21 x9 : 0000000000000000 x8 : 0000000000000001 x7 : 0000000000000000 x6 : ffff800080483190 x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000020 x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff8000936dabe0 dump_backtrace(regs = 00000000a214a9c4 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 soft_cursor+0x534/0x6bc drivers/video/fbdev/core/softcursor.c:74 bit_cursor+0xaac/0x112c drivers/video/fbdev/core/bitblit.c:370 fb_flashcursor+0x268/0x398 drivers/video/fbdev/core/fbcon.c:423 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0x91c/0x1250 kernel/workqueue.c:3479 worker_thread+0x798/0xbd0 kernel/workqueue.c:3560 kthread+0x304/0x3d4 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:854 Code: aa1a03e0 97b7aa67 aa1a03e0 d34416e9 (f8008415) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: aa1a03e0 mov x0, x26 4: 97b7aa67 bl 0xfffffffffedea9a0 8: aa1a03e0 mov x0, x26 c: d34416e9 ubfx x9, x23, #4, #2 * 10: f8008415 str x21, [x0], #8 <-- trapping instruction