On Sun, Sep 22, 2024 at 07:33:44PM GMT, Dennis Lam wrote: > This patch aims to fix a bug found by syzbot where a crash occurs due to > a divide by zero error in the bcachefs subsystem [1]. > > Bcachefs has a file called util.c that uses the function div_u64 to perform > division using 64-bit values. The function's parameters uses a 64-bit dividend > and a 32-bit divisor to perform its division, however sometimes in this file > a 64-bit divisor is passed using this function. When in use, the 64-bit value > is passed as a 32-bit value, creating the possibility of a division by zero > error. > > Therefore, this fix replaces the function div_u64 with div64_u64 where the > dividend and divisor is a 64-bit value to perform the correct division. > > [1] https://syzkaller.appspot.com/bug?extid=24beef64217854da05a4 > > Reported-and-tested-by: [email protected] > Signed-off-by: Dennis Lam <[email protected]>
We already have this, from Reed Riley 27663d7784b5 bcachefs: Replace div_u64 with div64_u64 where second param is u64
