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Unable to handle kernel NULL pointer dereference at virtual address 00000000
[00000000] *pgd=857ee003, *pmd=fe6b7003
Internal error: Oops: 80000207 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 671 Comm: syz-executor.1 Not tainted 6.0.0-rc3-syzkaller #0
Hardware name: ARM-Versatile Express
PC is at 0x0
LR is at gsmld_receive_buf+0xc0/0x15c drivers/tty/n_gsm.c:2861
pc : [<00000000>]    lr : [<808eaab4>]    psr: 60000013
sp : ec229e28  ip : 826efeb0  fp : ec229e6c
r10: 81de5c68  r9 : 825d5140  r8 : ec229e7c
r7 : 85678800  r6 : 00000000  r5 : ec229e7d  r4 : ec229e7c
r3 : 00000000  r2 : ec229e7c  r1 : 00000000  r0 : 85678800
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 30c5387d  Table: 85413e40  DAC: fffffffd
Register r0 information: slab kmalloc-512 start 85678800 pointer offset 0 size 512
Register r1 information: NULL pointer
Register r2 information: 2-page vmalloc region starting at 0xec228000 allocated at kernel_clone+0x9c/0x440 kernel/fork.c:2673
Register r3 information: NULL pointer
Register r4 information: 2-page vmalloc region starting at 0xec228000 allocated at kernel_clone+0x9c/0x440 kernel/fork.c:2673
Register r5 information: 2-page vmalloc region starting at 0xec228000 allocated at kernel_clone+0x9c/0x440 kernel/fork.c:2673
Register r6 information: NULL pointer
Register r7 information: slab kmalloc-512 start 85678800 pointer offset 0 size 512
Register r8 information: 2-page vmalloc region starting at 0xec228000 allocated at kernel_clone+0x9c/0x440 kernel/fork.c:2673
Register r9 information: non-slab/vmalloc memory
Register r10 information: non-slab/vmalloc memory
Register r11 information: 2-page vmalloc region starting at 0xec228000 allocated at kernel_clone+0x9c/0x440 kernel/fork.c:2673
Register r12 information: non-slab/vmalloc memory
Process syz-executor.1 (pid: 671, stack limit = 0xec228000)
Stack: (0xec229e28 to 0xec22a000)
9e20:                   8067b314 3f591507 85139e00 85139e18 81de5bc0 85139e00
9e40: 841be780 00000000 856010c0 85139e00 808ea9f4 841be780 20000000 85139a00
9e60: ec229f14 ec229e70 808dcfac 808eaa00 00000001 82979050 00000054 841be700
9e80: 00000003 00000036 ec229ee4 ec229e98 8068af1c 80680e64 00000001 00000054
9ea0: 00000012 ec229eb4 841d5a90 82c12c38 ec225412 3f59150b ec229ea8 81f4cdc0
9ec0: 20000000 3f591507 81f4c0dc 20000000 841be780 00005412 ec229ef4 ec229ee8
9ee0: 8068b020 3f591507 ec229f14 00005412 00000000 841be781 20000000 841be780
9f00: 00000003 82979050 ec229fa4 ec229f18 804b9814 808dc804 ec229f34 83e3a340
9f20: 83e3aa60 00000002 dddd26e8 5bb2a000 822a86f0 83e3a340 00000002 dddd26e8
9f40: ec229f5c ec229f50 8172d110 8172cfd8 ec229f84 ec229f60 8172cbe8 8172d100
9f60: 60000013 00000000 0012bfd0 00000036 60000010 3f591507 ec229f9c 00000000
9f80: 00000000 0012bfd0 00000036 80200288 83e3a340 00000036 00000000 ec229fa8
9fa0: 80200060 804b9710 00000000 00000000 00000003 00005412 20000000 00000000
9fc0: 00000000 00000000 0012bfd0 00000036 7ef523b2 76faf6d0 7ef52544 76faf20c
9fe0: 76faf020 76faf010 00016420 0004c150 60000010 00000003 00000000 00000000
Backtrace: 
[<808ea9f4>] (gsmld_receive_buf) from [<808dcfac>] (tiocsti drivers/tty/tty_io.c:2293 [inline])
[<808ea9f4>] (gsmld_receive_buf) from [<808dcfac>] (tty_ioctl+0x7b4/0xa6c drivers/tty/tty_io.c:2692)
 r10:85139a00 r9:20000000 r8:841be780 r7:808ea9f4 r6:85139e00 r5:856010c0
 r4:00000000
[<808dc7f8>] (tty_ioctl) from [<804b9814>] (vfs_ioctl fs/ioctl.c:51 [inline])
[<808dc7f8>] (tty_ioctl) from [<804b9814>] (do_vfs_ioctl fs/ioctl.c:830 [inline])
[<808dc7f8>] (tty_ioctl) from [<804b9814>] (__do_sys_ioctl fs/ioctl.c:868 [inline])
[<808dc7f8>] (tty_ioctl) from [<804b9814>] (sys_ioctl+0x110/0xa74 fs/ioctl.c:856)
 r10:82979050 r9:00000003 r8:841be780 r7:20000000 r6:841be781 r5:00000000
 r4:00005412
[<804b9704>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:64)
Exception stack(0xec229fa8 to 0xec229ff0)
9fa0:                   00000000 00000000 00000003 00005412 20000000 00000000
9fc0: 00000000 00000000 0012bfd0 00000036 7ef523b2 76faf6d0 7ef52544 76faf20c
9fe0: 76faf020 76faf010 00016420 0004c150
 r10:00000036 r9:83e3a340 r8:80200288 r7:00000036 r6:0012bfd0 r5:00000000
 r4:00000000
Code: bad PC value
---[ end trace 0000000000000000 ]---