Re: [syzbot] [block?] general protection fault in bio_iov_iter_get_pages

Hillf Danton
2025-09-07T08:19:59Z

> Date: Sun, 07 Sep 2025 00:11:35 -0700 [thread overview]
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: be5d4872e528 Add linux-next specific files for 20250905
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=17896962580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=a726684450a7d788
> dashboard link: https://syzkaller.appspot.com/bug?extid=b253ade8e1751d90a7a9
> compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10496962580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14a98962580000

#syz test

--- x/mm/gup.c
+++ y/mm/gup.c
@@ -2981,6 +2981,7 @@ static int gup_fast_pmd_leaf(pmd_t orig,
return 0;
}

+ pages += *nr;
*nr += refs;
for (; refs; refs--)
*(pages++) = page++;
@@ -3024,6 +3025,7 @@ static int gup_fast_pud_leaf(pud_t orig,
return 0;
}

+ pages += *nr;
*nr += refs;
for (; refs; refs--)
*(pages++) = page++;
--