* BUG: Bad rss-counter state (4) @ 2020-05-18 7:27 syzbot 2020-05-18 7:38 ` Dmitry Vyukov 2020-05-18 12:28 ` syzbot 0 siblings, 2 replies; 4+ messages in thread From: syzbot @ 2020-05-18 7:27 UTC (permalink / raw) To: linux-kernel, syzkaller-bugs Hello, syzbot found the following crash on: HEAD commit: ac935d22 Add linux-next specific files for 20200415 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=14b66e6e100000 kernel config: https://syzkaller.appspot.com/x/.config?x=bc498783097e9019 dashboard link: https://syzkaller.appspot.com/bug?extid=347e2331d03d06ab0224 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12d18e6e100000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=104170d6100000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+347e2331d03d06ab0224@syzkaller.appspotmail.com BUG: Bad rss-counter state mm:00000000a67744c9 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:00000000f49d6d70 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:0000000006212dd2 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:00000000b6ae35d3 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:00000000d44d5c2e type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:0000000023502204 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:000000001a912a5c type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:0000000072bd9e23 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:0000000053ee80f7 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:000000003cc0aff9 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:000000005a4ef043 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:00000000fe0ab895 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:00000000863004ed type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:0000000064449491 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:00000000f6a209ff type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:000000008100dc4b type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:00000000f80eb0e8 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:00000000475e50a5 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:00000000f2f5edcf type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:00000000bf721456 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:00000000d8d29ec3 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:00000000b5dff60e type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:000000001f0fe928 type:MM_ANONPAGES val:1 BUG: Bad rss-counter state mm:000000006fc01973 type:MM_ANONPAGES val:1 --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: BUG: Bad rss-counter state (4) 2020-05-18 7:27 BUG: Bad rss-counter state (4) syzbot @ 2020-05-18 7:38 ` Dmitry Vyukov 2020-05-18 12:28 ` syzbot 1 sibling, 0 replies; 4+ messages in thread From: Dmitry Vyukov @ 2020-05-18 7:38 UTC (permalink / raw) To: syzbot, Andrew Morton, Linux-MM; +Cc: LKML, syzkaller-bugs On Mon, May 18, 2020 at 9:27 AM syzbot <syzbot+347e2331d03d06ab0224@syzkaller.appspotmail.com> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: ac935d22 Add linux-next specific files for 20200415 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=14b66e6e100000 > kernel config: https://syzkaller.appspot.com/x/.config?x=bc498783097e9019 > dashboard link: https://syzkaller.appspot.com/bug?extid=347e2331d03d06ab0224 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12d18e6e100000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=104170d6100000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+347e2331d03d06ab0224@syzkaller.appspotmail.com This seems to be related to the mmap/mremap calls, +mm/mmap.c maintainers. > BUG: Bad rss-counter state mm:00000000a67744c9 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:00000000f49d6d70 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:0000000006212dd2 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:00000000b6ae35d3 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:00000000d44d5c2e type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:0000000023502204 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:000000001a912a5c type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:0000000072bd9e23 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:0000000053ee80f7 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:000000003cc0aff9 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:000000005a4ef043 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:00000000fe0ab895 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:00000000863004ed type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:0000000064449491 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:00000000f6a209ff type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:000000008100dc4b type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:00000000f80eb0e8 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:00000000475e50a5 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:00000000f2f5edcf type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:00000000bf721456 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:00000000d8d29ec3 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:00000000b5dff60e type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:000000001f0fe928 type:MM_ANONPAGES val:1 > BUG: Bad rss-counter state mm:000000006fc01973 type:MM_ANONPAGES val:1 > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/000000000000ada39605a5e71711%40google.com. ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: BUG: Bad rss-counter state (4) 2020-05-18 7:27 BUG: Bad rss-counter state (4) syzbot 2020-05-18 7:38 ` Dmitry Vyukov @ 2020-05-18 12:28 ` syzbot 2021-04-11 21:38 ` Vegard Nossum 1 sibling, 1 reply; 4+ messages in thread From: syzbot @ 2020-05-18 12:28 UTC (permalink / raw) To: a, akpm, ast, b.a.t.m.a.n, davem, dvyukov, jbacik, linux-kernel, linux-mm, mareklindner, mingo, netdev, peterz, songliubraving, sw, syzkaller-bugs, yhs syzbot has bisected this bug to: commit 0d8dd67be013727ae57645ecd3ea2c36365d7da8 Author: Song Liu <songliubraving@fb.com> Date: Wed Dec 6 22:45:14 2017 +0000 perf/headers: Sync new perf_event.h with the tools/include/uapi version bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13240a02100000 start commit: ac935d22 Add linux-next specific files for 20200415 git tree: linux-next final crash: https://syzkaller.appspot.com/x/report.txt?x=10a40a02100000 console output: https://syzkaller.appspot.com/x/log.txt?x=17240a02100000 kernel config: https://syzkaller.appspot.com/x/.config?x=bc498783097e9019 dashboard link: https://syzkaller.appspot.com/bug?extid=347e2331d03d06ab0224 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12d18e6e100000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=104170d6100000 Reported-by: syzbot+347e2331d03d06ab0224@syzkaller.appspotmail.com Fixes: 0d8dd67be013 ("perf/headers: Sync new perf_event.h with the tools/include/uapi version") For information about bisection process see: https://goo.gl/tpsmEJ#bisection ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Re: BUG: Bad rss-counter state (4) 2020-05-18 12:28 ` syzbot @ 2021-04-11 21:38 ` Vegard Nossum 0 siblings, 0 replies; 4+ messages in thread From: Vegard Nossum @ 2021-04-11 21:38 UTC (permalink / raw) To: syzbot, akpm, dvyukov, linux-kernel, linux-mm, mingo, netdev, peterz, syzkaller-bugs Cc: Hugh Dickins, Johannes Weiner, Song Liu (trimmed off the batman/bpf Ccs) On 2020-05-18 14:28, syzbot wrote: > syzbot has bisected this bug to: > > commit 0d8dd67be013727ae57645ecd3ea2c36365d7da8 > Author: Song Liu <songliubraving@fb.com> > Date: Wed Dec 6 22:45:14 2017 +0000 > > perf/headers: Sync new perf_event.h with the tools/include/uapi version > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13240a02100000 > start commit: ac935d22 Add linux-next specific files for 20200415 > git tree: linux-next > final crash: https://syzkaller.appspot.com/x/report.txt?x=10a40a02100000 > console output: https://syzkaller.appspot.com/x/log.txt?x=17240a02100000 > kernel config: https://syzkaller.appspot.com/x/.config?x=bc498783097e9019 > dashboard link: https://syzkaller.appspot.com/bug?extid=347e2331d03d06ab0224 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12d18e6e100000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=104170d6100000 > > Reported-by: syzbot+347e2331d03d06ab0224@syzkaller.appspotmail.com > Fixes: 0d8dd67be013 ("perf/headers: Sync new perf_event.h with the tools/include/uapi version") > > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > FWIW here's a nicer reproducer that more clearly shows what's really going on: #define _GNU_SOURCE #include <sys/mman.h> #include <linux/perf_event.h> #include <linux/hw_breakpoint.h> #include <fcntl.h> #include <stdio.h> #include <stdint.h> #include <string.h> #include <syscall.h> #include <unistd.h> // for compat with older perf headers #define uprobe_path config1 int main(int argc, char *argv[]) { // Find out what type id we need for uprobes int perf_type_pmu_uprobe; { FILE *fp = fopen("/sys/bus/event_source/devices/uprobe/type", "r"); fscanf(fp, "%d", &perf_type_pmu_uprobe); fclose(fp); } const char *filename = "./bus"; int fd = open(filename, O_RDWR|O_CREAT, 0600); write(fd, "x", 1); void *addr = mmap(NULL, 4096, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); // Register a perf uprobe on "./bus" struct perf_event_attr attr = {}; attr.type = perf_type_pmu_uprobe; attr.uprobe_path = (unsigned long) filename; syscall(__NR_perf_event_open, &attr, 0, 0, -1, 0); void *addr2 = mmap(NULL, 2 * 4096, PROT_NONE, MAP_PRIVATE, fd, 0); void *addr3 = mremap((void *) addr2, 4096, 2 * 4096, MREMAP_MAYMOVE); mremap(addr3, 4096, 4096, MREMAP_MAYMOVE | MREMAP_FIXED, (void *) addr2); return 0; } this instantly reproduces this output on current mainline for me: BUG: Bad rss-counter state mm:(____ptrval____) type:MM_ANONPAGES val:1 AFAICT the worst thing about this bug is that it shows up on anything that parses logs for "BUG"; it doesn't seem to have any ill effects other than messing up the rss counters. Although maybe it points to some underlying problem in uprobes/mm interaction. If I enable the "rss_stat" tracepoint and set ftrace_dump_on_oops=1, I see a trace roughly like this: perf_event_open() mmap(2 * 4096): - uprobe_mmap() - install_breakpoint() - __replace_page() - rss_stat: mm_id=0 curr=1 member=1 size=53248B mremap(4096 => 2 * 4096): - install_breakpoint() - __replace_page() - rss_stat: mm_id=0 curr=1 member=1 size=57344B - unmap_page_range() - rss_stat: mm_id=0 curr=1 member=1 size=53248B mremap(4096 => 4096): - move_vma() - copy_vma() - vma_merge() - install_breakpoint() - __replace_page() - rss_stat: mm_id=0 curr=1 member=1 size=57344B - do_munmap() - install_breakpoint(): - __replace_page() - rss_stat: mm_id=0 curr=1 member=1 size=61440B - unmap_page_range(): - rss_stat: mm_id=0 curr=1 member=1 size=57344B exit() - exit_mmap() - unmap_page_range(): - rss_stat: mm_id=0 curr=0 member=1 size=45056B - unmap_page_range(): - rss_stat: mm_id=0 curr=0 member=1 size=32768B - unmap_page_range(): - rss_stat: mm_id=0 curr=0 member=1 size=20480B - unmap_page_range(): - rss_stat: mm_id=0 curr=0 member=1 size=16384B - unmap_page_range(): - rss_stat: mm_id=0 curr=0 member=1 size=4096B What strikes me here is that at the end of the first mremap(), we have size 53248B (13 pages), but at the end of the second mremap(), we have size 57344B (14 pages), even though the second mremap() is only moving 1 page. So the second mremap() is bumping it up twice, but then only bumping down once. Vegard ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-04-11 21:39 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-05-18 7:27 BUG: Bad rss-counter state (4) syzbot 2020-05-18 7:38 ` Dmitry Vyukov 2020-05-18 12:28 ` syzbot 2021-04-11 21:38 ` Vegard Nossum
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