April 2018 - Linux-stable-mirror

FAILED: patch "[PATCH] ext4: force revalidation of directory pointer after" failed to apply to 4.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From e40ff213898502d299351cc2fe1e350cd186f0d3 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o <tytso(a)mit.edu> Date: Sun, 1 Apr 2018 23:21:03 -0400 Subject: [PATCH] ext4: force revalidation of directory pointer after seekdir(2) A malicious user could force the directory pointer to be in an invalid spot by using seekdir(2). Use the mechanism we already have to notice if the directory has changed since the last time we called ext4_readdir() to force a revalidation of the pointer. Reported-by: syzbot+1236ce66f79263e8a862(a)syzkaller.appspotmail.com Signed-off-by: Theodore Ts'o <tytso(a)mit.edu> Cc: stable(a)vger.kernel.org diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c index da87cf757f7d..e2902d394f1b 100644 --- a/fs/ext4/dir.c +++ b/fs/ext4/dir.c @@ -365,13 +365,15 @@ static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence) { struct inode *inode = file->f_mapping->host; int dx_dir = is_dx_dir(inode); - loff_t htree_max = ext4_get_htree_eof(file); + loff_t ret, htree_max = ext4_get_htree_eof(file); if (likely(dx_dir)) - return generic_file_llseek_size(file, offset, whence, + ret = generic_file_llseek_size(file, offset, whence, htree_max, htree_max); else - return ext4_llseek(file, offset, whence); + ret = ext4_llseek(file, offset, whence); + file->f_version = inode_peek_iversion(inode) - 1; + return ret; } /*

6 years, 9 months

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FAILED: patch "[PATCH] ext4: don't allow r/w mounts if metadata blocks overlap the" failed to apply to 4.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 18db4b4e6fc31eda838dd1c1296d67dbcb3dc957 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o <tytso(a)mit.edu> Date: Thu, 29 Mar 2018 22:10:35 -0400 Subject: [PATCH] ext4: don't allow r/w mounts if metadata blocks overlap the superblock If some metadata block, such as an allocation bitmap, overlaps the superblock, it's very likely that if the file system is mounted read/write, the results will not be pretty. So disallow r/w mounts for file systems corrupted in this particular way. Signed-off-by: Theodore Ts'o <tytso(a)mit.edu> Cc: stable(a)vger.kernel.org diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 7cd022c344d1..edcfe6956eba 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2335,6 +2335,8 @@ static int ext4_check_descriptors(struct super_block *sb, ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " "Block bitmap for group %u overlaps " "superblock", i); + if (!sb_rdonly(sb)) + return 0; } if (block_bitmap < first_block || block_bitmap > last_block) { ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " @@ -2347,6 +2349,8 @@ static int ext4_check_descriptors(struct super_block *sb, ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " "Inode bitmap for group %u overlaps " "superblock", i); + if (!sb_rdonly(sb)) + return 0; } if (inode_bitmap < first_block || inode_bitmap > last_block) { ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " @@ -2359,6 +2363,8 @@ static int ext4_check_descriptors(struct super_block *sb, ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " "Inode table for group %u overlaps " "superblock", i); + if (!sb_rdonly(sb)) + return 0; } if (inode_table < first_block || inode_table + sbi->s_itb_per_group - 1 > last_block) {

6 years, 9 months

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3.18.y queue build failure on arm64 and x86_64

by Harsh Shandilya

Hi Greg, Patch "usb: dwc3: pci: Properly cleanup resource" uses the `err` label which doesn't exist on 3.18, causing a build failure on at least the architectures mentioned in the subject line with allyesconfig. Changing `goto err` to `goto err3` resolves the build failure. Would you like me to send the fixed up patch or you would prefer to make the change by hand? -- Harsh Shandilya, PRJKT Development LLC

6 years, 9 months

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FAILED: patch "[PATCH] ext4: force revalidation of directory pointer after" failed to apply to 3.18-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 3.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From e40ff213898502d299351cc2fe1e350cd186f0d3 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o <tytso(a)mit.edu> Date: Sun, 1 Apr 2018 23:21:03 -0400 Subject: [PATCH] ext4: force revalidation of directory pointer after seekdir(2) A malicious user could force the directory pointer to be in an invalid spot by using seekdir(2). Use the mechanism we already have to notice if the directory has changed since the last time we called ext4_readdir() to force a revalidation of the pointer. Reported-by: syzbot+1236ce66f79263e8a862(a)syzkaller.appspotmail.com Signed-off-by: Theodore Ts'o <tytso(a)mit.edu> Cc: stable(a)vger.kernel.org diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c index da87cf757f7d..e2902d394f1b 100644 --- a/fs/ext4/dir.c +++ b/fs/ext4/dir.c @@ -365,13 +365,15 @@ static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence) { struct inode *inode = file->f_mapping->host; int dx_dir = is_dx_dir(inode); - loff_t htree_max = ext4_get_htree_eof(file); + loff_t ret, htree_max = ext4_get_htree_eof(file); if (likely(dx_dir)) - return generic_file_llseek_size(file, offset, whence, + ret = generic_file_llseek_size(file, offset, whence, htree_max, htree_max); else - return ext4_llseek(file, offset, whence); + ret = ext4_llseek(file, offset, whence); + file->f_version = inode_peek_iversion(inode) - 1; + return ret; } /*

6 years, 9 months

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FAILED: patch "[PATCH] ext4: don't allow r/w mounts if metadata blocks overlap the" failed to apply to 3.18-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 3.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 18db4b4e6fc31eda838dd1c1296d67dbcb3dc957 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o <tytso(a)mit.edu> Date: Thu, 29 Mar 2018 22:10:35 -0400 Subject: [PATCH] ext4: don't allow r/w mounts if metadata blocks overlap the superblock If some metadata block, such as an allocation bitmap, overlaps the superblock, it's very likely that if the file system is mounted read/write, the results will not be pretty. So disallow r/w mounts for file systems corrupted in this particular way. Signed-off-by: Theodore Ts'o <tytso(a)mit.edu> Cc: stable(a)vger.kernel.org diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 7cd022c344d1..edcfe6956eba 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2335,6 +2335,8 @@ static int ext4_check_descriptors(struct super_block *sb, ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " "Block bitmap for group %u overlaps " "superblock", i); + if (!sb_rdonly(sb)) + return 0; } if (block_bitmap < first_block || block_bitmap > last_block) { ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " @@ -2347,6 +2349,8 @@ static int ext4_check_descriptors(struct super_block *sb, ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " "Inode bitmap for group %u overlaps " "superblock", i); + if (!sb_rdonly(sb)) + return 0; } if (inode_bitmap < first_block || inode_bitmap > last_block) { ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " @@ -2359,6 +2363,8 @@ static int ext4_check_descriptors(struct super_block *sb, ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: " "Inode table for group %u overlaps " "superblock", i); + if (!sb_rdonly(sb)) + return 0; } if (inode_table < first_block || inode_table + sbi->s_itb_per_group - 1 > last_block) {

6 years, 9 months

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FAILED: patch "[PATCH] ext4: fail ext4_iget for root directory if unallocated" failed to apply to 3.18-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 3.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 8e4b5eae5decd9dfe5a4ee369c22028f90ab4c44 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o <tytso(a)mit.edu> Date: Thu, 29 Mar 2018 21:56:09 -0400 Subject: [PATCH] ext4: fail ext4_iget for root directory if unallocated If the root directory has an i_links_count of zero, then when the file system is mounted, then when ext4_fill_super() notices the problem and tries to call iput() the root directory in the error return path, ext4_evict_inode() will try to free the inode on disk, before all of the file system structures are set up, and this will result in an OOPS caused by a NULL pointer dereference. This issue has been assigned CVE-2018-1092. https://bugzilla.kernel.org/show_bug.cgi?id=199179 https://bugzilla.redhat.com/show_bug.cgi?id=1560777 Reported-by: Wen Xu <wen.xu(a)gatech.edu> Signed-off-by: Theodore Ts'o <tytso(a)mit.edu> Cc: stable(a)vger.kernel.org diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 435965598cb8..18aa2ef963ad 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4732,6 +4732,12 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) goto bad_inode; raw_inode = ext4_raw_inode(&iloc); + if ((ino == EXT4_ROOT_INO) && (raw_inode->i_links_count == 0)) { + EXT4_ERROR_INODE(inode, "root inode unallocated"); + ret = -EFSCORRUPTED; + goto bad_inode; + } + if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize); if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >

6 years, 9 months

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FAILED: patch "[PATCH] ext4: add validity checks for bitmap block numbers" failed to apply to 3.18-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 3.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 7dac4a1726a9c64a517d595c40e95e2d0d135f6f Mon Sep 17 00:00:00 2001 From: Theodore Ts'o <tytso(a)mit.edu> Date: Mon, 26 Mar 2018 23:54:10 -0400 Subject: [PATCH] ext4: add validity checks for bitmap block numbers An privileged attacker can cause a crash by mounting a crafted ext4 image which triggers a out-of-bounds read in the function ext4_valid_block_bitmap() in fs/ext4/balloc.c. This issue has been assigned CVE-2018-1093. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=199181 BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1560782 Reported-by: Wen Xu <wen.xu(a)gatech.edu> Signed-off-by: Theodore Ts'o <tytso(a)mit.edu> Cc: stable(a)vger.kernel.org diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index f82c4966f4ce..a33d8fb1bf2a 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -338,20 +338,25 @@ static ext4_fsblk_t ext4_valid_block_bitmap(struct super_block *sb, /* check whether block bitmap block number is set */ blk = ext4_block_bitmap(sb, desc); offset = blk - group_first_block; - if (!ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data)) + if (offset < 0 || EXT4_B2C(sbi, offset) >= sb->s_blocksize || + !ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data)) /* bad block bitmap */ return blk; /* check whether the inode bitmap block number is set */ blk = ext4_inode_bitmap(sb, desc); offset = blk - group_first_block; - if (!ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data)) + if (offset < 0 || EXT4_B2C(sbi, offset) >= sb->s_blocksize || + !ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data)) /* bad block bitmap */ return blk; /* check whether the inode table block number is set */ blk = ext4_inode_table(sb, desc); offset = blk - group_first_block; + if (offset < 0 || EXT4_B2C(sbi, offset) >= sb->s_blocksize || + EXT4_B2C(sbi, offset + sbi->s_itb_per_group) >= sb->s_blocksize) + return blk; next_zero_bit = ext4_find_next_zero_bit(bh->b_data, EXT4_B2C(sbi, offset + sbi->s_itb_per_group), EXT4_B2C(sbi, offset)); @@ -417,6 +422,7 @@ struct buffer_head * ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group) { struct ext4_group_desc *desc; + struct ext4_sb_info *sbi = EXT4_SB(sb); struct buffer_head *bh; ext4_fsblk_t bitmap_blk; int err; @@ -425,6 +431,12 @@ ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group) if (!desc) return ERR_PTR(-EFSCORRUPTED); bitmap_blk = ext4_block_bitmap(sb, desc); + if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) || + (bitmap_blk >= ext4_blocks_count(sbi->s_es))) { + ext4_error(sb, "Invalid block bitmap block %llu in " + "block_group %u", bitmap_blk, block_group); + return ERR_PTR(-EFSCORRUPTED); + } bh = sb_getblk(sb, bitmap_blk); if (unlikely(!bh)) { ext4_error(sb, "Cannot get buffer for block bitmap - " diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 3fa93665b4a3..df92e3ec9913 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -122,6 +122,7 @@ static struct buffer_head * ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group) { struct ext4_group_desc *desc; + struct ext4_sb_info *sbi = EXT4_SB(sb); struct buffer_head *bh = NULL; ext4_fsblk_t bitmap_blk; int err; @@ -131,6 +132,12 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group) return ERR_PTR(-EFSCORRUPTED); bitmap_blk = ext4_inode_bitmap(sb, desc); + if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) || + (bitmap_blk >= ext4_blocks_count(sbi->s_es))) { + ext4_error(sb, "Invalid inode bitmap blk %llu in " + "block_group %u", bitmap_blk, block_group); + return ERR_PTR(-EFSCORRUPTED); + } bh = sb_getblk(sb, bitmap_blk); if (unlikely(!bh)) { ext4_error(sb, "Cannot read inode bitmap - "

6 years, 9 months

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FAILED: patch "[PATCH] ext4: add bounds checking to ext4_xattr_find_entry()" failed to apply to 4.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 9496005d6ca4cf8f5ee8f828165a8956872dc59d Mon Sep 17 00:00:00 2001 From: Theodore Ts'o <tytso(a)mit.edu> Date: Fri, 30 Mar 2018 20:00:56 -0400 Subject: [PATCH] ext4: add bounds checking to ext4_xattr_find_entry() Add some paranoia checks to make sure we don't stray beyond the end of the valid memory region containing ext4 xattr entries while we are scanning for a match. Also rename the function to xattr_find_entry() since it is static and thus only used in fs/ext4/xattr.c Signed-off-by: Theodore Ts'o <tytso(a)mit.edu> Cc: stable(a)kernel.org diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index c030e41818ab..6304e81bfe6a 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -276,18 +276,22 @@ __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, __xattr_check_inode((inode), (header), (end), __func__, __LINE__) static int -ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index, - const char *name, int sorted) +xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry, + void *end, int name_index, const char *name, int sorted) { - struct ext4_xattr_entry *entry; + struct ext4_xattr_entry *entry, *next; size_t name_len; int cmp = 1; if (name == NULL) return -EINVAL; name_len = strlen(name); - entry = *pentry; - for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { + for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) { + next = EXT4_XATTR_NEXT(entry); + if ((void *) next >= end) { + EXT4_ERROR_INODE(inode, "corrupted xattr entries"); + return -EFSCORRUPTED; + } cmp = name_index - entry->e_name_index; if (!cmp) cmp = name_len - entry->e_name_len; @@ -509,6 +513,7 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, struct buffer_head *bh = NULL; struct ext4_xattr_entry *entry; size_t size; + void *end; int error; struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); @@ -530,7 +535,8 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, goto cleanup; ext4_xattr_block_cache_insert(ea_block_cache, bh); entry = BFIRST(bh); - error = ext4_xattr_find_entry(&entry, name_index, name, 1); + end = bh->b_data + bh->b_size; + error = xattr_find_entry(inode, &entry, end, name_index, name, 1); if (error) goto cleanup; size = le32_to_cpu(entry->e_value_size); @@ -579,7 +585,7 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, if (error) goto cleanup; entry = IFIRST(header); - error = ext4_xattr_find_entry(&entry, name_index, name, 0); + error = xattr_find_entry(inode, &entry, end, name_index, name, 0); if (error) goto cleanup; size = le32_to_cpu(entry->e_value_size); @@ -1808,8 +1814,8 @@ ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, bs->s.first = BFIRST(bs->bh); bs->s.end = bs->bh->b_data + bs->bh->b_size; bs->s.here = bs->s.first; - error = ext4_xattr_find_entry(&bs->s.here, i->name_index, - i->name, 1); + error = xattr_find_entry(inode, &bs->s.here, bs->s.end, + i->name_index, i->name, 1); if (error && error != -ENODATA) goto cleanup; bs->s.not_found = error; @@ -2168,8 +2174,8 @@ int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, if (error) return error; /* Find the named attribute. */ - error = ext4_xattr_find_entry(&is->s.here, i->name_index, - i->name, 0); + error = xattr_find_entry(inode, &is->s.here, is->s.end, + i->name_index, i->name, 0); if (error && error != -ENODATA) return error; is->s.not_found = error;

6 years, 9 months

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FAILED: patch "[PATCH] ext4: add bounds checking to ext4_xattr_find_entry()" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 9496005d6ca4cf8f5ee8f828165a8956872dc59d Mon Sep 17 00:00:00 2001 From: Theodore Ts'o <tytso(a)mit.edu> Date: Fri, 30 Mar 2018 20:00:56 -0400 Subject: [PATCH] ext4: add bounds checking to ext4_xattr_find_entry() Add some paranoia checks to make sure we don't stray beyond the end of the valid memory region containing ext4 xattr entries while we are scanning for a match. Also rename the function to xattr_find_entry() since it is static and thus only used in fs/ext4/xattr.c Signed-off-by: Theodore Ts'o <tytso(a)mit.edu> Cc: stable(a)kernel.org diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index c030e41818ab..6304e81bfe6a 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -276,18 +276,22 @@ __xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, __xattr_check_inode((inode), (header), (end), __func__, __LINE__) static int -ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index, - const char *name, int sorted) +xattr_find_entry(struct inode *inode, struct ext4_xattr_entry **pentry, + void *end, int name_index, const char *name, int sorted) { - struct ext4_xattr_entry *entry; + struct ext4_xattr_entry *entry, *next; size_t name_len; int cmp = 1; if (name == NULL) return -EINVAL; name_len = strlen(name); - entry = *pentry; - for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) { + for (entry = *pentry; !IS_LAST_ENTRY(entry); entry = next) { + next = EXT4_XATTR_NEXT(entry); + if ((void *) next >= end) { + EXT4_ERROR_INODE(inode, "corrupted xattr entries"); + return -EFSCORRUPTED; + } cmp = name_index - entry->e_name_index; if (!cmp) cmp = name_len - entry->e_name_len; @@ -509,6 +513,7 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, struct buffer_head *bh = NULL; struct ext4_xattr_entry *entry; size_t size; + void *end; int error; struct mb_cache *ea_block_cache = EA_BLOCK_CACHE(inode); @@ -530,7 +535,8 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, goto cleanup; ext4_xattr_block_cache_insert(ea_block_cache, bh); entry = BFIRST(bh); - error = ext4_xattr_find_entry(&entry, name_index, name, 1); + end = bh->b_data + bh->b_size; + error = xattr_find_entry(inode, &entry, end, name_index, name, 1); if (error) goto cleanup; size = le32_to_cpu(entry->e_value_size); @@ -579,7 +585,7 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, if (error) goto cleanup; entry = IFIRST(header); - error = ext4_xattr_find_entry(&entry, name_index, name, 0); + error = xattr_find_entry(inode, &entry, end, name_index, name, 0); if (error) goto cleanup; size = le32_to_cpu(entry->e_value_size); @@ -1808,8 +1814,8 @@ ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i, bs->s.first = BFIRST(bs->bh); bs->s.end = bs->bh->b_data + bs->bh->b_size; bs->s.here = bs->s.first; - error = ext4_xattr_find_entry(&bs->s.here, i->name_index, - i->name, 1); + error = xattr_find_entry(inode, &bs->s.here, bs->s.end, + i->name_index, i->name, 1); if (error && error != -ENODATA) goto cleanup; bs->s.not_found = error; @@ -2168,8 +2174,8 @@ int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, if (error) return error; /* Find the named attribute. */ - error = ext4_xattr_find_entry(&is->s.here, i->name_index, - i->name, 0); + error = xattr_find_entry(inode, &is->s.here, is->s.end, + i->name_index, i->name, 0); if (error && error != -ENODATA) return error; is->s.not_found = error;

6 years, 9 months

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FAILED: patch "[PATCH] ext4: add extra checks to ext4_xattr_block_get()" failed to apply to 4.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 54dd0e0a1b255f115f8647fc6fb93273251b01b9 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o <tytso(a)mit.edu> Date: Fri, 30 Mar 2018 20:04:11 -0400 Subject: [PATCH] ext4: add extra checks to ext4_xattr_block_get() Add explicit checks in ext4_xattr_block_get() just in case the e_value_offs and e_value_size fields in the the xattr block are corrupted in memory after the buffer_verified bit is set on the xattr block. Signed-off-by: Theodore Ts'o <tytso(a)mit.edu> Cc: stable(a)kernel.org diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 6304e81bfe6a..499cb4b1fbd2 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -197,7 +197,7 @@ ext4_xattr_check_entries(struct ext4_xattr_entry *entry, void *end, while (!IS_LAST_ENTRY(entry)) { u32 size = le32_to_cpu(entry->e_value_size); - if (size > INT_MAX) + if (size > EXT4_XATTR_SIZE_MAX) return -EFSCORRUPTED; if (size != 0 && entry->e_value_inum == 0) { @@ -540,8 +540,10 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, if (error) goto cleanup; size = le32_to_cpu(entry->e_value_size); + error = -ERANGE; + if (unlikely(size > EXT4_XATTR_SIZE_MAX)) + goto cleanup; if (buffer) { - error = -ERANGE; if (size > buffer_size) goto cleanup; if (entry->e_value_inum) { @@ -550,8 +552,12 @@ ext4_xattr_block_get(struct inode *inode, int name_index, const char *name, if (error) goto cleanup; } else { - memcpy(buffer, bh->b_data + - le16_to_cpu(entry->e_value_offs), size); + u16 offset = le16_to_cpu(entry->e_value_offs); + void *p = bh->b_data + offset; + + if (unlikely(p + size > end)) + goto cleanup; + memcpy(buffer, p, size); } } error = size; @@ -589,8 +595,10 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, if (error) goto cleanup; size = le32_to_cpu(entry->e_value_size); + error = -ERANGE; + if (unlikely(size > EXT4_XATTR_SIZE_MAX)) + goto cleanup; if (buffer) { - error = -ERANGE; if (size > buffer_size) goto cleanup; if (entry->e_value_inum) { @@ -599,8 +607,12 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, if (error) goto cleanup; } else { - memcpy(buffer, (void *)IFIRST(header) + - le16_to_cpu(entry->e_value_offs), size); + u16 offset = le16_to_cpu(entry->e_value_offs); + void *p = (void *)IFIRST(header) + offset; + + if (unlikely(p + size > end)) + goto cleanup; + memcpy(buffer, p, size); } } error = size; diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h index dd54c4f995c8..f39cad2abe2a 100644 --- a/fs/ext4/xattr.h +++ b/fs/ext4/xattr.h @@ -70,6 +70,17 @@ struct ext4_xattr_entry { EXT4_I(inode)->i_extra_isize)) #define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1)) +/* + * XATTR_SIZE_MAX is currently 64k, but for the purposes of checking + * for file system consistency errors, we use a somewhat bigger value. + * This allows XATTR_SIZE_MAX to grow in the future, but by using this + * instead of INT_MAX for certain consistency checks, we don't need to + * worry about arithmetic overflows. (Actually XATTR_SIZE_MAX is + * defined in include/uapi/linux/limits.h, so changing it is going + * not going to be trivial....) + */ +#define EXT4_XATTR_SIZE_MAX (1 << 24) + /* * The minimum size of EA value when you start storing it in an external inode * size of block - size of header - size of 1 entry - 4 null bytes

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Linux-stable-mirror April 2018