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Unable to handle kernel NULL pointer dereference at virtual address 00000000
[00000000] *pgd=85802003, *pmd=fe63c003
Internal error: Oops: 80000207 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 4541 Comm: syz-executor.0 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 : eb2f1e28  ip : 826efeb0  fp : eb2f1e6c
r10: 81de5c68  r9 : 825d5140  r8 : eb2f1e7c
r7 : 851faa00  r6 : 00000000  r5 : eb2f1e7d  r4 : eb2f1e7c
r3 : 00000000  r2 : eb2f1e7c  r1 : 00000000  r0 : 851faa00
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 30c5387d  Table: 859de280  DAC: fffffffd
Register r0 information: slab kmalloc-512 start 851faa00 pointer offset 0 size 512
Register r1 information: NULL pointer
Register r2 information: 2-page vmalloc region starting at 0xeb2f0000 allocated at kernel_clone+0x9c/0x440 kernel/fork.c:2673
Register r3 information: NULL pointer
Register r4 information: 2-page vmalloc region starting at 0xeb2f0000 allocated at kernel_clone+0x9c/0x440 kernel/fork.c:2673
Register r5 information: 2-page vmalloc region starting at 0xeb2f0000 allocated at kernel_clone+0x9c/0x440 kernel/fork.c:2673
Register r6 information: NULL pointer
Register r7 information: slab kmalloc-512 start 851faa00 pointer offset 0 size 512
Register r8 information: 2-page vmalloc region starting at 0xeb2f0000 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 0xeb2f0000 allocated at kernel_clone+0x9c/0x440 kernel/fork.c:2673
Register r12 information: non-slab/vmalloc memory
Process syz-executor.0 (pid: 4541, stack limit = 0xeb2f0000)
Stack: (0xeb2f1e28 to 0xeb2f2000)
1e20:                   8067b314 d809f32a 850e1c00 850e1c18 81de5bc0 850e1c00
1e40: 832a3480 00000000 85919b00 850e1c00 808ea9f4 832a3480 20000000 850e1e00
1e60: eb2f1f14 eb2f1e70 808dcfac 808eaa00 00000001 83138e50 00000054 832a3400
1e80: 00000003 00000036 eb2f1ee4 eb2f1e98 8068af1c 80680e64 00000001 00000054
1ea0: 00000012 eb2f1eb4 841c9c10 834dfcc0 eb2f5412 d809f30b eb2f1ea8 81f4cdc0
1ec0: 20000000 d809f32a 81f4c0dc 20000000 832a3480 00005412 eb2f1ef4 eb2f1ee8
1ee0: 8068b020 d809f32a eb2f1f14 00005412 00000000 832a3481 20000000 832a3480
1f00: 00000003 83138e50 eb2f1fa4 eb2f1f18 804b9814 808dc804 eb2f1f34 83288000
1f20: 83288720 00000002 dddd26e8 5bb2a000 822a86f0 83288000 00000002 dddd26e8
1f40: eb2f1f5c eb2f1f50 8172d110 8172cfd8 eb2f1f84 eb2f1f60 8172cbe8 8172d100
1f60: 60000013 00000000 0012bfd0 00000036 60000010 d809f32a eb2f1f9c 00000000
1f80: 00000000 0012bfd0 00000036 80200288 83288000 00000036 00000000 eb2f1fa8
1fa0: 80200060 804b9710 00000000 00000000 00000003 00005412 20000000 00000000
1fc0: 00000000 00000000 0012bfd0 00000036 7eae93b2 76f496d0 7eae9544 76f4920c
1fe0: 76f49020 76f49010 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)
 r10:850e1e00 r9:20000000 r8:832a3480 r7:808ea9f4 r6:850e1c00 r5:85919b00
 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)
 r10:83138e50 r9:00000003 r8:832a3480 r7:20000000 r6:832a3481 r5:00000000
 r4:00005412
[<804b9704>] (sys_ioctl) from [<80200060>] (ret_fast_syscall+0x0/0x1c arch/arm/mm/proc-v7.S:64)
Exception stack(0xeb2f1fa8 to 0xeb2f1ff0)
1fa0:                   00000000 00000000 00000003 00005412 20000000 00000000
1fc0: 00000000 00000000 0012bfd0 00000036 7eae93b2 76f496d0 7eae9544 76f4920c
1fe0: 76f49020 76f49010 00016420 0004c150
 r10:00000036 r9:83288000 r8:80200288 r7:00000036 r6:0012bfd0 r5:00000000
 r4:00000000
Code: bad PC value
---[ end trace 0000000000000000 ]---