On Mon, Mar 18, 2024 at 9:58 AM syzbot <syzbot+adbc983a1588b7805de3@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: e5eb28f6d1af Merge tag 'mm-nonmm-stable-2024-03-14-09-36' .. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=13043abe180000 > kernel config: https://syzkaller.appspot.com/x/.config?x=19bb57c23dffc38e > dashboard link: https://syzkaller.appspot.com/bug?extid=adbc983a1588b7805de3 > compiler: arm-linux-gnueabi-gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 > userspace arch: arm > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1706d231180000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13ba7959180000 > > Downloadable assets: > disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/8ead8862021c/non_bootable_disk-e5eb28f6.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/0a7371c63ff2/vmlinux-e5eb28f6.xz > kernel image: https://storage.googleapis.com/syzbot-assets/7539441b4add/zImage-e5eb28f6.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+adbc983a1588b7805de3@xxxxxxxxxxxxxxxxxxxxxxxxx > > ------------[ cut here ]------------ > kernel BUG at include/linux/scatterlist.h:187! Looks like the provided buffer is invalid: #ifdef CONFIG_DEBUG_SG BUG_ON(!virt_addr_valid(buf)); #endif which is "src" from: sg_init_one(&input, src, entry->length); Looking at the surrounding code and recent history, there's this commit that stands out: mm/zswap: remove the memcpy if acomp is not sleepable (sha: 270700dd06ca41a4779c19eb46608f076bb7d40e) which has the effect of, IIUC, using the zpool mapped memory directly as src, instead of acomp_ctx->buffer (which was previously the case, as zsmalloc was not sleepable). This might not necessarily be a bug with that commit itself, but might have revealed another bug elsewhere. Anyway, cc-ing the author, Barry Song, to fact check me :) Will take a closer look later.
