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BUG: KASAN: use-after-free in __fb_pad_aligned_buffer include/linux/fb.h:654 [inline]
BUG: KASAN: use-after-free in bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
BUG: KASAN: use-after-free in bit_putcs+0x103a/0x1bf0 drivers/video/fbdev/core/bitblit.c:185
Read of size 1 at addr ffff8880a780e869 by task syz-executor.2/10484

CPU: 1 PID: 10484 Comm: syz-executor.2 Not tainted 5.9.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d6/0x29e lib/dump_stack.c:118
 print_address_description+0x66/0x620 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report+0x132/0x1d0 mm/kasan/report.c:530
 __fb_pad_aligned_buffer include/linux/fb.h:654 [inline]
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:96 [inline]
 bit_putcs+0x103a/0x1bf0 drivers/video/fbdev/core/bitblit.c:185
 fbcon_putcs+0x790/0xaf0 drivers/video/fbdev/core/fbcon.c:1308
 con_flush drivers/tty/vt/vt.c:2575 [inline]
 do_con_write+0xd42b/0xd580 drivers/tty/vt/vt.c:2916
 con_write+0x20/0x40 drivers/tty/vt/vt.c:3250
 process_output_block drivers/tty/n_tty.c:595 [inline]
 n_tty_write+0xcbf/0x1170 drivers/tty/n_tty.c:2333
 do_tty_write drivers/tty/tty_io.c:962 [inline]
 tty_write+0x593/0x940 drivers/tty/tty_io.c:1046
 do_loop_readv_writev fs/read_write.c:737 [inline]
 do_iter_write+0x441/0x610 fs/read_write.c:1020
 vfs_writev fs/read_write.c:1091 [inline]
 do_writev+0x23f/0x4a0 fs/read_write.c:1134
 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45dd99
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fce9db0bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 000000000003a680 RCX: 000000000045dd99
RDX: 0000000000000001 RSI: 00000000200005c0 RDI: 0000000000000003
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007fffae9fa67f R14: 00007fce9db0c9c0 R15: 000000000118bf2c

Allocated by task 16:
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0xde/0x4f0 net/core/skbuff.c:210
 skb_copy+0xe8/0x750 net/core/skbuff.c:1514
 mac80211_hwsim_tx_frame_no_nl+0xc8c/0x15e0 drivers/net/wireless/mac80211_hwsim.c:1446
 mac80211_hwsim_tx_frame+0x143/0x180 drivers/net/wireless/mac80211_hwsim.c:1654
 mac80211_hwsim_beacon_tx+0x3dd/0x6f0 drivers/net/wireless/mac80211_hwsim.c:1694
 __iterate_interfaces+0x1e1/0x440 net/mac80211/util.c:737
 ieee80211_iterate_active_interfaces_atomic+0x9b/0x120 net/mac80211/util.c:773
 mac80211_hwsim_beacon+0xa4/0x180 drivers/net/wireless/mac80211_hwsim.c:1717
 __run_hrtimer kernel/time/hrtimer.c:1524 [inline]
 __hrtimer_run_queues+0x47f/0x930 kernel/time/hrtimer.c:1588
 hrtimer_run_softirq+0x15a/0x1b0 kernel/time/hrtimer.c:1605
 __do_softirq+0x256/0x6d5 kernel/softirq.c:298

The buggy address belongs to the object at ffff8880a780e800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 105 bytes inside of
 512-byte region [ffff8880a780e800, ffff8880a780ea00)
The buggy address belongs to the page:
page:000000002cc44c3f refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880a780e800 pfn:0xa780e
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea000256c8c8 ffffea00025e5d48 ffff8880aa440600
raw: ffff8880a780e800 ffff8880a780e000 0000000100000002 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a780e700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a780e780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a780e800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff8880a780e880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a780e900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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