From 41bbc527cc027ffca402f8679038bdab7afce4ec Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 27 Nov 2020 16:18:17 +0100 Subject: [PATCH] 4.9-stable patches added patches: btrfs-inode-verify-inode-mode-to-avoid-null-pointer-dereference.patch btrfs-tree-checker-enhance-chunk-checker-to-validate-chunk-profile.patch --- ...de-to-avoid-null-pointer-dereference.patch | 197 ++++++++++++++++++ ...nk-checker-to-validate-chunk-profile.patch | 45 ++++ queue-4.9/series | 2 + 3 files changed, 244 insertions(+) create mode 100644 queue-4.9/btrfs-inode-verify-inode-mode-to-avoid-null-pointer-dereference.patch create mode 100644 queue-4.9/btrfs-tree-checker-enhance-chunk-checker-to-validate-chunk-profile.patch diff --git a/queue-4.9/btrfs-inode-verify-inode-mode-to-avoid-null-pointer-dereference.patch b/queue-4.9/btrfs-inode-verify-inode-mode-to-avoid-null-pointer-dereference.patch new file mode 100644 index 00000000000..2536f7fbdd0 --- /dev/null +++ b/queue-4.9/btrfs-inode-verify-inode-mode-to-avoid-null-pointer-dereference.patch @@ -0,0 +1,197 @@ +From foo@baz Fri Nov 27 04:15:29 PM CET 2020 +From: Qu Wenruo +Date: Wed, 13 Mar 2019 13:55:11 +0800 +Subject: btrfs: inode: Verify inode mode to avoid NULL pointer dereference + +From: Qu Wenruo + +commit 6bf9e4bd6a277840d3fe8c5d5d530a1fbd3db592 upstream + +[BUG] +When accessing a file on a crafted image, btrfs can crash in block layer: + + BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 + PGD 136501067 P4D 136501067 PUD 124519067 PMD 0 + CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.0.0-rc8-default #252 + RIP: 0010:end_bio_extent_readpage+0x144/0x700 + Call Trace: + + blk_update_request+0x8f/0x350 + blk_mq_end_request+0x1a/0x120 + blk_done_softirq+0x99/0xc0 + __do_softirq+0xc7/0x467 + irq_exit+0xd1/0xe0 + call_function_single_interrupt+0xf/0x20 + + RIP: 0010:default_idle+0x1e/0x170 + +[CAUSE] +The crafted image has a tricky corruption, the INODE_ITEM has a +different type against its parent dir: + + item 20 key (268 INODE_ITEM 0) itemoff 2808 itemsize 160 + generation 13 transid 13 size 1048576 nbytes 1048576 + block group 0 mode 121644 links 1 uid 0 gid 0 rdev 0 + sequence 9 flags 0x0(none) + +This mode number 0120000 means it's a symlink. + +But the dir item think it's still a regular file: + + item 8 key (264 DIR_INDEX 5) itemoff 3707 itemsize 32 + location key (268 INODE_ITEM 0) type FILE + transid 13 data_len 0 name_len 2 + name: f4 + item 40 key (264 DIR_ITEM 51821248) itemoff 1573 itemsize 32 + location key (268 INODE_ITEM 0) type FILE + transid 13 data_len 0 name_len 2 + name: f4 + +For symlink, we don't set BTRFS_I(inode)->io_tree.ops and leave it +empty, as symlink is only designed to have inlined extent, all handled +by tree block read. Thus no need to trigger btrfs_submit_bio_hook() for +inline file extent. + +However end_bio_extent_readpage() expects tree->ops populated, as it's +reading regular data extent. This causes NULL pointer dereference. + +[FIX] +This patch fixes the problem in two ways: + +- Verify inode mode against its dir item when looking up inode + So in btrfs_lookup_dentry() if we find inode mode mismatch with dir + item, we error out so that corrupted inode will not be accessed. + +- Verify inode mode when getting extent mapping + Only regular file should have regular or preallocated extent. + If we found regular/preallocated file extent for symlink or + the rest, we error out before submitting the read bio. + +With this fix that crafted image can be rejected gracefully: + + BTRFS critical (device loop0): inode mode mismatch with dir: inode mode=0121644 btrfs type=7 dir type=1 + +Reported-by: Yoon Jungyeon +Link: https://bugzilla.kernel.org/show_bug.cgi?id=202763 +Reviewed-by: Nikolay Borisov +Signed-off-by: Qu Wenruo +Signed-off-by: David Sterba +[sudip: use original btrfs_inode_type(), btrfs_crit with root->fs_info, +ISREG with inode->i_mode and adjust context] +Signed-off-by: Sudip Mukherjee +Signed-off-by: Greg Kroah-Hartman +--- + fs/btrfs/inode.c | 41 +++++++++++++++++++++++++++++++++-------- + fs/btrfs/tests/inode-tests.c | 1 + + 2 files changed, 34 insertions(+), 8 deletions(-) + +--- a/fs/btrfs/inode.c ++++ b/fs/btrfs/inode.c +@@ -5440,11 +5440,13 @@ no_delete: + } + + /* +- * this returns the key found in the dir entry in the location pointer. ++ * Return the key found in the dir entry in the location pointer, fill @type ++ * with BTRFS_FT_*, and return 0. ++ * + * If no dir entries were found, location->objectid is 0. + */ + static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry, +- struct btrfs_key *location) ++ struct btrfs_key *location, u8 *type) + { + const char *name = dentry->d_name.name; + int namelen = dentry->d_name.len; +@@ -5466,6 +5468,8 @@ static int btrfs_inode_by_name(struct in + goto out_err; + + btrfs_dir_item_key_to_cpu(path->nodes[0], di, location); ++ if (!ret) ++ *type = btrfs_dir_type(path->nodes[0], di); + out: + btrfs_free_path(path); + return ret; +@@ -5755,19 +5759,25 @@ static struct inode *new_simple_dir(stru + return inode; + } + ++static inline u8 btrfs_inode_type(struct inode *inode) ++{ ++ return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT]; ++} ++ + struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) + { + struct inode *inode; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_root *sub_root = root; + struct btrfs_key location; ++ u8 di_type = 0; + int index; + int ret = 0; + + if (dentry->d_name.len > BTRFS_NAME_LEN) + return ERR_PTR(-ENAMETOOLONG); + +- ret = btrfs_inode_by_name(dir, dentry, &location); ++ ret = btrfs_inode_by_name(dir, dentry, &location, &di_type); + if (ret < 0) + return ERR_PTR(ret); + +@@ -5776,6 +5786,18 @@ struct inode *btrfs_lookup_dentry(struct + + if (location.type == BTRFS_INODE_ITEM_KEY) { + inode = btrfs_iget(dir->i_sb, &location, root, NULL); ++ if (IS_ERR(inode)) ++ return inode; ++ ++ /* Do extra check against inode mode with di_type */ ++ if (btrfs_inode_type(inode) != di_type) { ++ btrfs_crit(root->fs_info, ++"inode mode mismatch with dir: inode mode=0%o btrfs type=%u dir type=%u", ++ inode->i_mode, btrfs_inode_type(inode), ++ di_type); ++ iput(inode); ++ return ERR_PTR(-EUCLEAN); ++ } + return inode; + } + +@@ -6391,11 +6413,6 @@ fail: + return ERR_PTR(ret); + } + +-static inline u8 btrfs_inode_type(struct inode *inode) +-{ +- return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT]; +-} +- + /* + * utility function to add 'inode' into 'parent_inode' with + * a give name and a given sequence number. +@@ -6981,6 +6998,14 @@ again: + extent_start = found_key.offset; + if (found_type == BTRFS_FILE_EXTENT_REG || + found_type == BTRFS_FILE_EXTENT_PREALLOC) { ++ /* Only regular file could have regular/prealloc extent */ ++ if (!S_ISREG(inode->i_mode)) { ++ ret = -EUCLEAN; ++ btrfs_crit(root->fs_info, ++ "regular/prealloc extent found for non-regular inode %llu", ++ btrfs_ino(inode)); ++ goto out; ++ } + extent_end = extent_start + + btrfs_file_extent_num_bytes(leaf, item); + } else if (found_type == BTRFS_FILE_EXTENT_INLINE) { +--- a/fs/btrfs/tests/inode-tests.c ++++ b/fs/btrfs/tests/inode-tests.c +@@ -245,6 +245,7 @@ static noinline int test_btrfs_get_exten + return ret; + } + ++ inode->i_mode = S_IFREG; + BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY; + BTRFS_I(inode)->location.objectid = BTRFS_FIRST_FREE_OBJECTID; + BTRFS_I(inode)->location.offset = 0; diff --git a/queue-4.9/btrfs-tree-checker-enhance-chunk-checker-to-validate-chunk-profile.patch b/queue-4.9/btrfs-tree-checker-enhance-chunk-checker-to-validate-chunk-profile.patch new file mode 100644 index 00000000000..5bd2a80499e --- /dev/null +++ b/queue-4.9/btrfs-tree-checker-enhance-chunk-checker-to-validate-chunk-profile.patch @@ -0,0 +1,45 @@ +From foo@baz Fri Nov 27 04:15:29 PM CET 2020 +From: Qu Wenruo +Date: Wed, 13 Mar 2019 12:17:50 +0800 +Subject: btrfs: tree-checker: Enhance chunk checker to validate chunk profile + +From: Qu Wenruo + +commit 80e46cf22ba0bcb57b39c7c3b52961ab3a0fd5f2 upstream + +Btrfs-progs already have a comprehensive type checker, to ensure there +is only 0 (SINGLE profile) or 1 (DUP/RAID0/1/5/6/10) bit set for chunk +profile bits. + +Do the same work for kernel. + +Reported-by: Yoon Jungyeon +Link: https://bugzilla.kernel.org/show_bug.cgi?id=202765 +Reviewed-by: Nikolay Borisov +Reviewed-by: Johannes Thumshirn +Signed-off-by: Qu Wenruo +Reviewed-by: David Sterba +Signed-off-by: David Sterba +[sudip: manually backport, use btrfs_err with root->fs_info] +Signed-off-by: Sudip Mukherjee +Signed-off-by: Greg Kroah-Hartman +--- + fs/btrfs/volumes.c | 7 +++++++ + 1 file changed, 7 insertions(+) + +--- a/fs/btrfs/volumes.c ++++ b/fs/btrfs/volumes.c +@@ -6414,6 +6414,13 @@ static int btrfs_check_chunk_valid(struc + return -EIO; + } + ++ if (!is_power_of_2(type & BTRFS_BLOCK_GROUP_PROFILE_MASK) && ++ (type & BTRFS_BLOCK_GROUP_PROFILE_MASK) != 0) { ++ btrfs_err(root->fs_info, ++ "invalid chunk profile flag: 0x%llx, expect 0 or 1 bit set", ++ type & BTRFS_BLOCK_GROUP_PROFILE_MASK); ++ return -EUCLEAN; ++ } + if ((type & BTRFS_BLOCK_GROUP_TYPE_MASK) == 0) { + btrfs_err(root->fs_info, "missing chunk type flag: 0x%llx", type); + return -EIO; diff --git a/queue-4.9/series b/queue-4.9/series index 07e9cd1655f..3d8a3fa7727 100644 --- a/queue-4.9/series +++ b/queue-4.9/series @@ -1,3 +1,5 @@ perf-event-check-ref_reloc_sym-before-using-it.patch mm-userfaultfd-do-not-access-vma-vm_mm-after-calling-handle_userfault.patch pci-add-device-even-if-driver-attach-failed.patch +btrfs-tree-checker-enhance-chunk-checker-to-validate-chunk-profile.patch +btrfs-inode-verify-inode-mode-to-avoid-null-pointer-dereference.patch -- 2.47.3