[PATCH openEuler-1.0-LTS 1/4] ext4: fix bug_on in __es_tree_search caused by bad quota inode
From: Baokun Li libaokun1@huawei.com
hulk inclusion category: bugfix bugzilla: 187821,https://gitee.com/openeuler/kernel/issues/I5X9U0 CVE: NA
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We got a issue as fllows: Reviewed-by: Zhang Yi yi.zhang@huawei.com
================================================================== kernel BUG at fs/ext4/extents_status.c:202! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 1 PID: 810 Comm: mount Not tainted 6.1.0-rc1-next-g9631525255e3 #352 RIP: 0010:__es_tree_search.isra.0+0xb8/0xe0 RSP: 0018:ffffc90001227900 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000077512a0f RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000002a10 RDI: ffff8881004cd0c8 RBP: ffff888177512ac8 R08: 47ffffffffffffff R09: 0000000000000001 R10: 0000000000000001 R11: 00000000000679af R12: 0000000000002a10 R13: ffff888177512d88 R14: 0000000077512a10 R15: 0000000000000000 FS: 00007f4bd76dbc40(0000)GS:ffff88842fd00000(0000)knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005653bf993cf8 CR3: 000000017bfdf000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ext4_es_cache_extent+0xe2/0x210 ext4_cache_extents+0xd2/0x110 ext4_find_extent+0x5d5/0x8c0 ext4_ext_map_blocks+0x9c/0x1d30 ext4_map_blocks+0x431/0xa50 ext4_getblk+0x82/0x340 ext4_bread+0x14/0x110 ext4_quota_read+0xf0/0x180 v2_read_header+0x24/0x90 v2_check_quota_file+0x2f/0xa0 dquot_load_quota_sb+0x26c/0x760 dquot_load_quota_inode+0xa5/0x190 ext4_enable_quotas+0x14c/0x300 __ext4_fill_super+0x31cc/0x32c0 ext4_fill_super+0x115/0x2d0 get_tree_bdev+0x1d2/0x360 ext4_get_tree+0x19/0x30 vfs_get_tree+0x26/0xe0 path_mount+0x81d/0xfc0 do_mount+0x8d/0xc0 __x64_sys_mount+0xc0/0x160 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK> ==================================================================
Above issue may happen as follows: ------------------------------------- ext4_fill_super ext4_orphan_cleanup ext4_enable_quotas ext4_quota_enable ext4_iget --> get error inode <5> ext4_ext_check_inode --> Wrong imode makes it escape inspection make_bad_inode(inode) --> EXT4_BOOT_LOADER_INO set imode dquot_load_quota_inode vfs_setup_quota_inode --> check pass dquot_load_quota_sb v2_check_quota_file v2_read_header ext4_quota_read ext4_bread ext4_getblk ext4_map_blocks ext4_ext_map_blocks ext4_find_extent ext4_cache_extents ext4_es_cache_extent __es_tree_search.isra.0 ext4_es_end --> Wrong extents trigger BUG_ON
In the above issue, s_usr_quota_inum is set to 5, but inode<5> contains incorrect imode and disordered extents. Because 5 is EXT4_BOOT_LOADER_INO, the ext4_ext_check_inode check in the ext4_iget function can be bypassed, finally, the extents that are not checked trigger the BUG_ON in the __es_tree_search function. To solve this issue, check whether the inode is bad_inode in vfs_setup_quota_inode().
Signed-off-by: Baokun Li libaokun1@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- fs/quota/dquot.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index ddb379abd919..316f49cbc032 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -2312,6 +2312,10 @@ static int vfs_load_quota_inode(struct inode *inode, int type, int format_id,
if (!fmt) return -ESRCH; + if (is_bad_inode(inode)) { + error = -EUCLEAN; + goto out_fmt; + } if (!S_ISREG(inode->i_mode)) { error = -EACCES; goto out_fmt;
From: Baokun Li libaokun1@huawei.com
hulk inclusion category: bugfix bugzilla: 187821,https://gitee.com/openeuler/kernel/issues/I5X9U0 CVE: NA
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Before quota is enabled, a check on the preset quota inums in ext4_super_block is added to prevent wrong quota inodes from being loaded. In addition, when the quota fails to be enabled, the quota type and quota inum are printed to facilitate fault locating.
Signed-off-by: Baokun Li libaokun1@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- fs/ext4/super.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 37a2e66b77a7..2faad105a945 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -6134,6 +6134,20 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id, return err; }
+static inline bool ext4_check_quota_inum(int type, unsigned long qf_inum) +{ + switch (type) { + case USRQUOTA: + return qf_inum == EXT4_USR_QUOTA_INO; + case GRPQUOTA: + return qf_inum == EXT4_GRP_QUOTA_INO; + case PRJQUOTA: + return qf_inum >= EXT4_GOOD_OLD_FIRST_INO; + default: + BUG(); + } +} + static int ext4_quota_enable(struct super_block *sb, int type, int format_id, unsigned int flags) { @@ -6150,9 +6164,16 @@ static int ext4_quota_enable(struct super_block *sb, int type, int format_id, if (!qf_inums[type]) return -EPERM;
+ if (!ext4_check_quota_inum(type, qf_inums[type])) { + ext4_error(sb, "Bad quota inum: %lu, type: %d", + qf_inums[type], type); + return -EUCLEAN; + } + qf_inode = ext4_iget(sb, qf_inums[type], EXT4_IGET_SPECIAL); if (IS_ERR(qf_inode)) { - ext4_error(sb, "Bad quota inode # %lu", qf_inums[type]); + ext4_error(sb, "Bad quota inode: %lu, type: %d", + qf_inums[type], type); return PTR_ERR(qf_inode); }
@@ -6191,8 +6212,9 @@ static int ext4_enable_quotas(struct super_block *sb) if (err) { ext4_warning(sb, "Failed to enable quota tracking " - "(type=%d, err=%d). Please run " - "e2fsck to fix.", type, err); + "(type=%d, err=%d, ino=%lu). " + "Please run e2fsck to fix.", type, + err, qf_inums[type]); for (type--; type >= 0; type--) { struct inode *inode;
From: Baokun Li libaokun1@huawei.com
hulk inclusion category: bugfix bugzilla: 187821,https://gitee.com/openeuler/kernel/issues/I5X9U0 CVE: NA
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There are many places that will get unhappy (and crash) when ext4_iget() returns a bad inode. However, if iget the boot loader inode, allows a bad inode to be returned, because the inode may not be initialized. This mechanism can be used to bypass some checks and cause panic. To solve this problem, we add a special iget flag EXT4_IGET_BAD. Only with this flag we'd be returning bad inode from ext4_iget(), otherwise we always return the error code if the inode is bad inode.(suggested by Jan Kara)
Signed-off-by: Baokun Li libaokun1@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- fs/ext4/ext4.h | 3 ++- fs/ext4/inode.c | 8 +++++++- fs/ext4/ioctl.c | 3 ++- 3 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 6efc710b07bf..4c88e75180a2 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2569,7 +2569,8 @@ int do_journal_get_write_access(handle_t *handle, typedef enum { EXT4_IGET_NORMAL = 0, EXT4_IGET_SPECIAL = 0x0001, /* OK to iget a system inode */ - EXT4_IGET_HANDLE = 0x0002 /* Inode # is from a handle */ + EXT4_IGET_HANDLE = 0x0002, /* Inode # is from a handle */ + EXT4_IGET_BAD = 0x0004 /* Allow to iget a bad inode */ } ext4_iget_flags;
extern struct inode *__ext4_iget(struct super_block *sb, unsigned long ino, diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index ce88148cdc4a..6006842c679c 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5268,8 +5268,14 @@ struct inode *__ext4_iget(struct super_block *sb, unsigned long ino, "iget: bogus i_mode (%o)", inode->i_mode); goto bad_inode; } - brelse(iloc.bh); + if (is_bad_inode(inode) && !(flags & EXT4_IGET_BAD)) { + ext4_error_inode(inode, function, line, 0, + "bad inode without EXT4_IGET_BAD flag"); + ret = -EUCLEAN; + goto bad_inode; + }
+ brelse(iloc.bh); unlock_new_inode(inode); return inode;
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index 3c8324715e65..7efceafe8830 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -121,7 +121,8 @@ static long swap_inode_boot_loader(struct super_block *sb, blkcnt_t blocks; unsigned short bytes;
- inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO, EXT4_IGET_SPECIAL); + inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO, + EXT4_IGET_SPECIAL | EXT4_IGET_BAD); if (IS_ERR(inode_bl)) return PTR_ERR(inode_bl); ei_bl = EXT4_I(inode_bl);
From: Baokun Li libaokun1@huawei.com
hulk inclusion category: bugfix bugzilla: 187821,https://gitee.com/openeuler/kernel/issues/I5X9U0 CVE: NA
--------------------------------
We got a issue as fllows: Reviewed-by: Zhang Yi yi.zhang@huawei.com
================================================================== kernel BUG at fs/ext4/extents_status.c:203! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 1 PID: 945 Comm: cat Not tainted 6.0.0-next-20221007-dirty #349 RIP: 0010:ext4_es_end.isra.0+0x34/0x42 RSP: 0018:ffffc9000143b768 EFLAGS: 00010203 RAX: 0000000000000000 RBX: ffff8881769cd0b8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8fc27cf7 RDI: 00000000ffffffff RBP: ffff8881769cd0bc R08: 0000000000000000 R09: ffffc9000143b5f8 R10: 0000000000000001 R11: 0000000000000001 R12: ffff8881769cd0a0 R13: ffff8881768e5668 R14: 00000000768e52f0 R15: 0000000000000000 FS: 00007f359f7f05c0(0000)GS:ffff88842fd00000(0000)knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f359f5a2000 CR3: 000000017130c000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __es_tree_search.isra.0+0x6d/0xf5 ext4_es_cache_extent+0xfa/0x230 ext4_cache_extents+0xd2/0x110 ext4_find_extent+0x5d5/0x8c0 ext4_ext_map_blocks+0x9c/0x1d30 ext4_map_blocks+0x431/0xa50 ext4_mpage_readpages+0x48e/0xe40 ext4_readahead+0x47/0x50 read_pages+0x82/0x530 page_cache_ra_unbounded+0x199/0x2a0 do_page_cache_ra+0x47/0x70 page_cache_ra_order+0x242/0x400 ondemand_readahead+0x1e8/0x4b0 page_cache_sync_ra+0xf4/0x110 filemap_get_pages+0x131/0xb20 filemap_read+0xda/0x4b0 generic_file_read_iter+0x13a/0x250 ext4_file_read_iter+0x59/0x1d0 vfs_read+0x28f/0x460 ksys_read+0x73/0x160 __x64_sys_read+0x1e/0x30 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK> ==================================================================
In the above issue, ioctl invokes the swap_inode_boot_loader function to swap inode<5> and inode<12>. However, inode<5> contain incorrect imode and disordered extents, and i_nlink is set to 1. The extents check for inode in the ext4_iget function can be bypassed bacause 5 is EXT4_BOOT_LOADER_INO. While links_count is set to 1, the extents are not initialized in swap_inode_boot_loader. After the ioctl command is executed successfully, the extents are swapped to inode<12>, in this case, run the `cat` command to view inode<12>. And Bug_ON is triggered due to the incorrect extents.
When the boot loader inode is not initialized, its imode can be one of the following: 1) the imode is a bad type, which is marked as bad_inode in ext4_iget and set to S_IFREG. 2) the imode is good type but not S_IFREG. 3) the imode is S_IFREG.
The BUG_ON may be triggered by bypassing the check in cases 1 and 2. Therefore, when the boot loader inode is bad_inode or its imode is not S_IFREG, initialize the inode to avoid triggering the BUG.
Signed-off-by: Baokun Li libaokun1@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- fs/ext4/ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index 7efceafe8830..4a5f9a41c519 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -172,7 +172,7 @@ static long swap_inode_boot_loader(struct super_block *sb, /* Protect extent tree against block allocations via delalloc */ ext4_double_down_write_data_sem(inode, inode_bl);
- if (inode_bl->i_nlink == 0) { + if (is_bad_inode(inode_bl) || !S_ISREG(inode_bl->i_mode)) { /* this inode has never been used as a BOOT_LOADER */ set_nlink(inode_bl, 1); i_uid_write(inode_bl, 0);
-
Yongqiang Liu