| Message ID | 20220208201918.627085-2-joseph.salisbury@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | Fix for CVE-2021-3506 | expand |
On Tue, Feb 8, 2022 at 12:20 PM Joseph Salisbury < joseph.salisbury@canonical.com> wrote: > From: Chao Yu <yuchao0@huawei.com> > > butt3rflyh4ck <butterflyhuangxx@gmail.com> reported a bug found by > syzkaller fuzzer with custom modifications in 5.12.0-rc3+ [1]: > > dump_stack+0xfa/0x151 lib/dump_stack.c:120 > print_address_description.constprop.0.cold+0x82/0x32c > mm/kasan/report.c:232 > __kasan_report mm/kasan/report.c:399 [inline] > kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416 > f2fs_test_bit fs/f2fs/f2fs.h:2572 [inline] > current_nat_addr fs/f2fs/node.h:213 [inline] > get_next_nat_page fs/f2fs/node.c:123 [inline] > __flush_nat_entry_set fs/f2fs/node.c:2888 [inline] > f2fs_flush_nat_entries+0x258e/0x2960 fs/f2fs/node.c:2991 > f2fs_write_checkpoint+0x1372/0x6a70 fs/f2fs/checkpoint.c:1640 > f2fs_issue_checkpoint+0x149/0x410 fs/f2fs/checkpoint.c:1807 > f2fs_sync_fs+0x20f/0x420 fs/f2fs/super.c:1454 > __sync_filesystem fs/sync.c:39 [inline] > sync_filesystem fs/sync.c:67 [inline] > sync_filesystem+0x1b5/0x260 fs/sync.c:48 > generic_shutdown_super+0x70/0x370 fs/super.c:448 > kill_block_super+0x97/0xf0 fs/super.c:1394 > > The root cause is, if nat entry in checkpoint journal area is corrupted, > e.g. nid of journalled nat entry exceeds max nid value, during checkpoint, > once it tries to flush nat journal to NAT area, get_next_nat_page() may > access out-of-bounds memory on nat_bitmap due to it uses wrong nid value > as bitmap offset. > > [1] > https://lore.kernel.org/lkml/CAFcO6XOMWdr8pObek6eN6-fs58KG9doRFadgJj-FnF-1x43s2g@mail.gmail.com/T/#u > > Reported-and-tested-by: butt3rflyh4ck <butterflyhuangxx@gmail.com> > Signed-off-by: Chao Yu <yuchao0@huawei.com> > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> > (backported from commit b862676e371715456c9dade7990c8004996d0d9e) > [jsalisbury: Preserved name of function check_nid_range() due to later > commit > 4d57b86dd86404fd8bb4f87d277d5a86a7fe537e, which changes name to > f2fs_check_nid_range] > CVE-2021-3506 > Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com> > --- > fs/f2fs/node.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > index 70428dd6f797..1b1f061ea6e1 100644 > --- a/fs/f2fs/node.c > +++ b/fs/f2fs/node.c > @@ -2406,6 +2406,9 @@ static void remove_nats_in_journal(struct > f2fs_sb_info *sbi) > struct f2fs_nat_entry raw_ne; > nid_t nid = le32_to_cpu(nid_in_journal(journal, i)); > > + if (check_nid_range(sbi, nid)) > + continue; > + > raw_ne = nat_in_journal(journal, i); > > ne = __lookup_nat_cache(nm_i, nid); > -- > 2.32.0 > > Acked-by: Luke Nowakowski-Krijger <luke.nowakowskikrijger@canonical.com> - Luke > -- > kernel-team mailing list > kernel-team@lists.ubuntu.com > https://lists.ubuntu.com/mailman/listinfo/kernel-team >
On 08.02.22 21:19, Joseph Salisbury wrote: > From: Chao Yu <yuchao0@huawei.com> > > butt3rflyh4ck <butterflyhuangxx@gmail.com> reported a bug found by > syzkaller fuzzer with custom modifications in 5.12.0-rc3+ [1]: > > dump_stack+0xfa/0x151 lib/dump_stack.c:120 > print_address_description.constprop.0.cold+0x82/0x32c mm/kasan/report.c:232 > __kasan_report mm/kasan/report.c:399 [inline] > kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416 > f2fs_test_bit fs/f2fs/f2fs.h:2572 [inline] > current_nat_addr fs/f2fs/node.h:213 [inline] > get_next_nat_page fs/f2fs/node.c:123 [inline] > __flush_nat_entry_set fs/f2fs/node.c:2888 [inline] > f2fs_flush_nat_entries+0x258e/0x2960 fs/f2fs/node.c:2991 > f2fs_write_checkpoint+0x1372/0x6a70 fs/f2fs/checkpoint.c:1640 > f2fs_issue_checkpoint+0x149/0x410 fs/f2fs/checkpoint.c:1807 > f2fs_sync_fs+0x20f/0x420 fs/f2fs/super.c:1454 > __sync_filesystem fs/sync.c:39 [inline] > sync_filesystem fs/sync.c:67 [inline] > sync_filesystem+0x1b5/0x260 fs/sync.c:48 > generic_shutdown_super+0x70/0x370 fs/super.c:448 > kill_block_super+0x97/0xf0 fs/super.c:1394 > > The root cause is, if nat entry in checkpoint journal area is corrupted, > e.g. nid of journalled nat entry exceeds max nid value, during checkpoint, > once it tries to flush nat journal to NAT area, get_next_nat_page() may > access out-of-bounds memory on nat_bitmap due to it uses wrong nid value > as bitmap offset. > > [1] https://lore.kernel.org/lkml/CAFcO6XOMWdr8pObek6eN6-fs58KG9doRFadgJj-FnF-1x43s2g@mail.gmail.com/T/#u > > Reported-and-tested-by: butt3rflyh4ck <butterflyhuangxx@gmail.com> > Signed-off-by: Chao Yu <yuchao0@huawei.com> > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> > (backported from commit b862676e371715456c9dade7990c8004996d0d9e) > [jsalisbury: Preserved name of function check_nid_range() due to later commit > 4d57b86dd86404fd8bb4f87d277d5a86a7fe537e, which changes name to > f2fs_check_nid_range] > CVE-2021-3506 > Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com> Acked-by: Stefan Bader <stefan.bader@canonical.com> > --- > fs/f2fs/node.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > index 70428dd6f797..1b1f061ea6e1 100644 > --- a/fs/f2fs/node.c > +++ b/fs/f2fs/node.c > @@ -2406,6 +2406,9 @@ static void remove_nats_in_journal(struct f2fs_sb_info *sbi) > struct f2fs_nat_entry raw_ne; > nid_t nid = le32_to_cpu(nid_in_journal(journal, i)); > > + if (check_nid_range(sbi, nid)) > + continue; > + > raw_ne = nat_in_journal(journal, i); > > ne = __lookup_nat_cache(nm_i, nid);
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 70428dd6f797..1b1f061ea6e1 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -2406,6 +2406,9 @@ static void remove_nats_in_journal(struct f2fs_sb_info *sbi) struct f2fs_nat_entry raw_ne; nid_t nid = le32_to_cpu(nid_in_journal(journal, i)); + if (check_nid_range(sbi, nid)) + continue; + raw_ne = nat_in_journal(journal, i); ne = __lookup_nat_cache(nm_i, nid);