general protection fault in anon_vma_interval_tree_remove

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: fb893de3 Merge tag 'tag-chrome-platform-for-v5.9' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16dfbd06900000
kernel config: https://syzkaller.appspot.com/x/.config?x=f1fedc63022bf07e
dashboard link: https://syzkaller.appspot.com/bug?extid=1a977da4a4ffcc20290d
compiler: gcc (GCC) 10.1.0-syz 20200507
CC: [ak...@linux-foundation.org linux-...@vger.kernel.org linu...@kvack.org]

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1a977d...@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc00134a283e: 0000 [#1] PREEMPT SMP KASAN
KASAN: probably user-memory-access in range [0x000000009a5141f0-0x000000009a5141f7]
CPU: 1 PID: 15437 Comm: syz-executor.1 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:173 [inline]
RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:216 [inline]
RIP: 0010:rb_erase_augmented include/linux/rbtree_augmented.h:303 [inline]
RIP: 0010:rb_erase_augmented_cached include/linux/rbtree_augmented.h:314 [inline]
RIP: 0010:__anon_vma_interval_tree_remove mm/interval_tree.c:71 [inline]
RIP: 0010:anon_vma_interval_tree_remove+0x93b/0xf40 mm/interval_tree.c:88
Code: e3 e8 89 42 d2 ff 4d 85 e4 0f 84 89 01 00 00 e8 db 45 d2 ff 4d 8d 7c 24 10 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 0f 05 00 00 48 8b 44 24 10 49 3b 44 24 10 0f 84
RSP: 0018:ffffc9001af4f910 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 000000009a5141e0 RCX: ffffffff81a203a7
RDX: 00000000134a283e RSI: ffffffff81a203b5 RDI: 0000000000000007
RBP: 0000000000000000 R08: ffff8880a0fa03b0 R09: ffff88809a54b117
R10: 0000000000000000 R11: 0000000000000000 R12: 000000009a5141e0
R13: 000000009a5141e0 R14: 0000000000000000 R15: 000000009a5141f0
FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe28c26cf0 CR3: 00000000a6bde000 CR4: 00000000001526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
unlink_anon_vmas+0x218/0x830 mm/rmap.c:402
free_pgtables+0xe2/0x2f0 mm/memory.c:398
exit_mmap+0x2c0/0x530 mm/mmap.c:3184
__mmput+0x122/0x470 kernel/fork.c:1076
mmput+0x53/0x60 kernel/fork.c:1097
exit_mm kernel/exit.c:483 [inline]
do_exit+0xa8b/0x29f0 kernel/exit.c:793
do_group_exit+0x125/0x310 kernel/exit.c:903
get_signal+0x40b/0x1ee0 kernel/signal.c:2743
arch_do_signal+0x82/0x2520 arch/x86/kernel/signal.c:811
exit_to_user_mode_loop kernel/entry/common.c:135 [inline]
exit_to_user_mode_prepare+0x172/0x1d0 kernel/entry/common.c:166
syscall_exit_to_user_mode+0x59/0x2b0 kernel/entry/common.c:241
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d189
Code: Bad RIP value.
RSP: 002b:00007fd3dea68cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000000 RBX: 000000000118cf48 RCX: 000000000045d189
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000118cf48
RBP: 000000000118cf40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 000000000169fb6f R14: 00007fd3dea699c0 R15: 000000000118cf4c
Modules linked in:
---[ end trace dd98c5e2b940452f ]---
RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:173 [inline]
RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:216 [inline]
RIP: 0010:rb_erase_augmented include/linux/rbtree_augmented.h:303 [inline]
RIP: 0010:rb_erase_augmented_cached include/linux/rbtree_augmented.h:314 [inline]
RIP: 0010:__anon_vma_interval_tree_remove mm/interval_tree.c:71 [inline]
RIP: 0010:anon_vma_interval_tree_remove+0x93b/0xf40 mm/interval_tree.c:88
Code: e3 e8 89 42 d2 ff 4d 85 e4 0f 84 89 01 00 00 e8 db 45 d2 ff 4d 8d 7c 24 10 48 b8 00 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 0f 05 00 00 48 8b 44 24 10 49 3b 44 24 10 0f 84
RSP: 0018:ffffc9001af4f910 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 000000009a5141e0 RCX: ffffffff81a203a7
RDX: 00000000134a283e RSI: ffffffff81a203b5 RDI: 0000000000000007
RBP: 0000000000000000 R08: ffff8880a0fa03b0 R09: ffff88809a54b117
R10: 0000000000000000 R11: 0000000000000000 R12: 000000009a5141e0
R13: 000000009a5141e0 R14: 0000000000000000 R15: 000000009a5141f0
FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc50b4efd8 CR3: 00000001e3c0f000 CR4: 00000000001526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.