On Sat 03-08-19 05:06:43, Minchan Kim wrote: > On Fri, Aug 02, 2019 at 10:58:05AM -0700, syzbot wrote: > > Hello, > > > > syzbot found the following crash on: > > > > HEAD commit: 0d8b3265 Add linux-next specific files for 20190729 > > git tree: linux-next > > console output: https://syzkaller.appspot.com/x/log.txt?x=1663c7d0600000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=ae96f3b8a7e885f7 > > dashboard link: https://syzkaller.appspot.com/bug?extid=8e6326965378936537c3 > > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=133c437c600000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15645854600000 > > > > The bug was bisected to: > > > > commit 06a833a1167e9cbb43a9a4317ec24585c6ec85cb > > Author: Minchan Kim <minchan@xxxxxxxxxx> > > Date: Sat Jul 27 05:12:38 2019 +0000 > > > > mm: introduce MADV_PAGEOUT > > > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1545f764600000 > > final crash: https://syzkaller.appspot.com/x/report.txt?x=1745f764600000 > > console output: https://syzkaller.appspot.com/x/log.txt?x=1345f764600000 > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+8e6326965378936537c3@xxxxxxxxxxxxxxxxxxxxxxxxx > > Fixes: 06a833a1167e ("mm: introduce MADV_PAGEOUT") > > > > raw: 01fffc0000090025 dead000000000100 dead000000000122 ffff88809c49f741 > > raw: 0000000000020000 0000000000000000 00000002ffffffff ffff88821b6eaac0 > > page dumped because: VM_BUG_ON_PAGE(PageActive(page)) > > page->mem_cgroup:ffff88821b6eaac0 > > ------------[ cut here ]------------ > > kernel BUG at mm/vmscan.c:1156! > > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > > CPU: 1 PID: 9846 Comm: syz-executor110 Not tainted 5.3.0-rc2-next-20190729 > > #54 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > Google 01/01/2011 > > RIP: 0010:shrink_page_list+0x2872/0x5430 mm/vmscan.c:1156 > > My old version had PG_active flag clear but it seems to lose it with revising > patchsets. Thanks, Sizbot! > > >From 66d64988619ef7e86b0002b2fc20fdf5b84ad49c Mon Sep 17 00:00:00 2001 > From: Minchan Kim <minchan@xxxxxxxxxx> > Date: Sat, 3 Aug 2019 04:54:02 +0900 > Subject: [PATCH] mm: Clear PG_active on MADV_PAGEOUT > > shrink_page_list expects every pages as argument should be no active > LRU pages so we need to clear PG_active. Ups, missed that during review. > > Reported-by: syzbot+8e6326965378936537c3@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: 06a833a1167e ("mm: introduce MADV_PAGEOUT") This is not a valid sha1 because it likely comes from linux-next. I guess Andrew will squash it into mm-introduce-madv_pageout.patch Just for the record Acked-by: Michal Hocko <mhocko@xxxxxxxx> And thanks for syzkaller to exercise the new interface so quickly! > Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> > --- > mm/vmscan.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 47aa2158cfac2..e2a8d3f5bbe48 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2181,6 +2181,7 @@ unsigned long reclaim_pages(struct list_head *page_list) > } > > if (nid == page_to_nid(page)) { > + ClearPageActive(page); > list_move(&page->lru, &node_page_list); > continue; > } > -- > 2.22.0.770.g0f2c4a37fd-goog -- Michal Hocko SUSE Labs
