| Message ID | 20201008191522.1948889-1-ebiggers@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | f2fs: reject CASEFOLD inode flag without casefold feature | expand |
Eric Biggers <ebiggers@kernel.org> writes: > From: Eric Biggers <ebiggers@google.com> > > syzbot reported: > > general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN > KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] > CPU: 0 PID: 6860 Comm: syz-executor835 Not tainted 5.9.0-rc8-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:utf8_casefold+0x43/0x1b0 fs/unicode/utf8-core.c:107 > [...] > Call Trace: > f2fs_init_casefolded_name fs/f2fs/dir.c:85 [inline] > __f2fs_setup_filename fs/f2fs/dir.c:118 [inline] > f2fs_prepare_lookup+0x3bf/0x640 fs/f2fs/dir.c:163 > f2fs_lookup+0x10d/0x920 fs/f2fs/namei.c:494 > __lookup_hash+0x115/0x240 fs/namei.c:1445 > filename_create+0x14b/0x630 fs/namei.c:3467 > user_path_create fs/namei.c:3524 [inline] > do_mkdirat+0x56/0x310 fs/namei.c:3664 > do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > [...] > > The problem is that an inode has F2FS_CASEFOLD_FL set, but the > filesystem doesn't have the casefold feature flag set, and therefore > super_block::s_encoding is NULL. > > Fix this by making sanity_check_inode() reject inodes that have > F2FS_CASEFOLD_FL when the filesystem doesn't have the casefold feature. > > Reported-by: syzbot+05139c4039d0679e19ff@syzkaller.appspotmail.com > Fixes: 2c2eb7a300cd ("f2fs: Support case-insensitive file name lookups") > Signed-off-by: Eric Biggers <ebiggers@google.com> Looks good. For the record, this is fixed on ext4 already. Reviewed-by: Gabriel Krisman Bertazi <krisman@collabora.com>
On 2020/10/9 3:15, Eric Biggers wrote: > From: Eric Biggers <ebiggers@google.com> > > syzbot reported: > > general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN > KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] > CPU: 0 PID: 6860 Comm: syz-executor835 Not tainted 5.9.0-rc8-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:utf8_casefold+0x43/0x1b0 fs/unicode/utf8-core.c:107 > [...] > Call Trace: > f2fs_init_casefolded_name fs/f2fs/dir.c:85 [inline] > __f2fs_setup_filename fs/f2fs/dir.c:118 [inline] > f2fs_prepare_lookup+0x3bf/0x640 fs/f2fs/dir.c:163 > f2fs_lookup+0x10d/0x920 fs/f2fs/namei.c:494 > __lookup_hash+0x115/0x240 fs/namei.c:1445 > filename_create+0x14b/0x630 fs/namei.c:3467 > user_path_create fs/namei.c:3524 [inline] > do_mkdirat+0x56/0x310 fs/namei.c:3664 > do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > [...] > > The problem is that an inode has F2FS_CASEFOLD_FL set, but the > filesystem doesn't have the casefold feature flag set, and therefore > super_block::s_encoding is NULL. > > Fix this by making sanity_check_inode() reject inodes that have > F2FS_CASEFOLD_FL when the filesystem doesn't have the casefold feature. > > Reported-by: syzbot+05139c4039d0679e19ff@syzkaller.appspotmail.com > Fixes: 2c2eb7a300cd ("f2fs: Support case-insensitive file name lookups") > Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Thanks,
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index 2ed935c13aed..d5664bc7d6c6 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -287,6 +287,13 @@ static bool sanity_check_inode(struct inode *inode, struct page *node_page) return false; } + if ((fi->i_flags & F2FS_CASEFOLD_FL) && !f2fs_sb_has_casefold(sbi)) { + set_sbi_flag(sbi, SBI_NEED_FSCK); + f2fs_warn(sbi, "%s: inode (ino=%lx) has casefold flag, but casefold feature is off", + __func__, inode->i_ino); + return false; + } + if (f2fs_has_extra_attr(inode) && f2fs_sb_has_compression(sbi) && fi->i_flags & F2FS_COMPR_FL && F2FS_FITS_IN_INODE(ri, fi->i_extra_isize,