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path: root/fs/ext4/fsmap.c
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2023-10-28ext4: Convert to bdev_open_by_dev()Jan Kara1-4/+5
Convert ext4 to use bdev_open_by_dev() and pass the handle around. CC: linux-ext4@vger.kernel.org CC: Ted Tso <tytso@mit.edu> Acked-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230927093442.25915-22-jack@suse.cz Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-03-07ext4: fix another off-by-one fsmap error on 1k block filesystemsDarrick J. Wong1-0/+2
Apparently syzbot figured out that issuing this FSMAP call: struct fsmap_head cmd = { .fmh_count = ...; .fmh_keys = { { .fmr_device = /* ext4 dev */, .fmr_physical = 0, }, { .fmr_device = /* ext4 dev */, .fmr_physical = 0, }, }, ... }; ret = ioctl(fd, FS_IOC_GETFSMAP, &cmd); Produces this crash if the underlying filesystem is a 1k-block ext4 filesystem: kernel BUG at fs/ext4/ext4.h:3331! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 3 PID: 3227965 Comm: xfs_io Tainted: G W O 6.2.0-rc8-achx Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 RIP: 0010:ext4_mb_load_buddy_gfp+0x47c/0x570 [ext4] RSP: 0018:ffffc90007c03998 EFLAGS: 00010246 RAX: ffff888004978000 RBX: ffffc90007c03a20 RCX: ffff888041618000 RDX: 0000000000000000 RSI: 00000000000005a4 RDI: ffffffffa0c99b11 RBP: ffff888012330000 R08: ffffffffa0c2b7d0 R09: 0000000000000400 R10: ffffc90007c03950 R11: 0000000000000000 R12: 0000000000000001 R13: 00000000ffffffff R14: 0000000000000c40 R15: ffff88802678c398 FS: 00007fdf2020c880(0000) GS:ffff88807e100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd318a5fe8 CR3: 000000007f80f001 CR4: 00000000001706e0 Call Trace: <TASK> ext4_mballoc_query_range+0x4b/0x210 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80] ext4_getfsmap_datadev+0x713/0x890 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80] ext4_getfsmap+0x2b7/0x330 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80] ext4_ioc_getfsmap+0x153/0x2b0 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80] __ext4_ioctl+0x2a7/0x17e0 [ext4 dfa189daddffe8fecd3cdfd00564e0f265a8ab80] __x64_sys_ioctl+0x82/0xa0 do_syscall_64+0x2b/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7fdf20558aff RSP: 002b:00007ffd318a9e30 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000000200c0 RCX: 00007fdf20558aff RDX: 00007fdf1feb2010 RSI: 00000000c0c0583b RDI: 0000000000000003 RBP: 00005625c0634be0 R08: 00005625c0634c40 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdf1feb2010 R13: 00005625be70d994 R14: 0000000000000800 R15: 0000000000000000 For GETFSMAP calls, the caller selects a physical block device by writing its block number into fsmap_head.fmh_keys[01].fmr_device. To query mappings for a subrange of the device, the starting byte of the range is written to fsmap_head.fmh_keys[0].fmr_physical and the last byte of the range goes in fsmap_head.fmh_keys[1].fmr_physical. IOWs, to query what mappings overlap with bytes 3-14 of /dev/sda, you'd set the inputs as follows: fmh_keys[0] = { .fmr_device = major(8, 0), .fmr_physical = 3}, fmh_keys[1] = { .fmr_device = major(8, 0), .fmr_physical = 14}, Which would return you whatever is mapped in the 12 bytes starting at physical offset 3. The crash is due to insufficient range validation of keys[1] in ext4_getfsmap_datadev. On 1k-block filesystems, block 0 is not part of the filesystem, which means that s_first_data_block is nonzero. ext4_get_group_no_and_offset subtracts this quantity from the blocknr argument before cracking it into a group number and a block number within a group. IOWs, block group 0 spans blocks 1-8192 (1-based) instead of 0-8191 (0-based) like what happens with larger blocksizes. The net result of this encoding is that blocknr < s_first_data_block is not a valid input to this function. The end_fsb variable is set from the keys that are copied from userspace, which means that in the above example, its value is zero. That leads to an underflow here: blocknr = blocknr - le32_to_cpu(es->s_first_data_block); The division then operates on -1: offset = do_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb)) >> EXT4_SB(sb)->s_cluster_bits; Leaving an impossibly large group number (2^32-1) in blocknr. ext4_getfsmap_check_keys checked that keys[0].fmr_physical and keys[1].fmr_physical are in increasing order, but ext4_getfsmap_datadev adjusts keys[0].fmr_physical to be at least s_first_data_block. This implies that we have to check it again after the adjustment, which is the piece that I forgot. Reported-by: syzbot+6be2b977c89f79b6b153@syzkaller.appspotmail.com Fixes: 4a4956249dac ("ext4: fix off-by-one fsmap error on 1k block filesystems") Link: https://syzkaller.appspot.com/bug?id=79d5768e9bfe362911ac1a5057a36fc6b5c30002 Cc: stable@vger.kernel.org Signed-off-by: Darrick J. Wong <djwong@kernel.org> Link: https://lore.kernel.org/r/Y+58NPTH7VNGgzdd@magnolia Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2021-04-08treewide: Change list_sort to use const pointersSami Tolvanen1-2/+2
list_sort() internally casts the comparison function passed to it to a different type with constant struct list_head pointers, and uses this pointer to call the functions, which trips indirect call Control-Flow Integrity (CFI) checking. Instead of removing the consts, this change defines the list_cmp_func_t type and changes the comparison function types of all list_sort() callers to use const pointers, thus avoiding type mismatches. Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Kees Cook <keescook@chromium.org> Tested-by: Nick Desaulniers <ndesaulniers@google.com> Tested-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20210408182843.1754385-10-samitolvanen@google.com
2020-11-06jbd2: rename j_maxlen to j_total_len and add jbd2_journal_max_txn_bufsHarshad Shirwadkar1-1/+1
The on-disk superblock field sb->s_maxlen represents the total size of the journal including the fast commit area and is no more the max number of blocks available for a transaction. The maximum number of blocks available to a transaction is reduced by the number of fast commit blocks. So, this patch renames j_maxlen to j_total_len to better represent its intent. Also, it adds a function to calculate max number of bufs available for a transaction. Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/20201106035911.1942128-6-harshadshirwadkar@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: limit entries returned when counting fsmap recordsDarrick J. Wong1-0/+3
If userspace asked fsmap to try to count the number of entries, we cannot return more than UINT_MAX entries because fmh_entries is u32. Therefore, stop counting if we hit this limit or else we will waste time to return truncated results. Fixes: 0c9ec4beecac ("ext4: support GETFSMAP ioctls") Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Link: https://lore.kernel.org/r/20201001222148.GA49520@magnolia Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-10-18ext4: rename journal_dev to s_journal_dev inside ext4_sb_infoChunguang Xu1-4/+4
Rename journal_dev to s_journal_dev inside ext4_sb_info, keep the naming rules consistent with other variables, which is convenient for code reading and writing. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Link: https://lore.kernel.org/r/1600916623-544-1-git-send-email-brookxu@tencent.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-05-12ext4: fix miscellaneous sparse warningsTheodore Ts'o1-1/+1
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-05-10ext4: make function ‘ext4_getfsmap_find_fixed_metadata’ staticMathieu Malaterre1-2/+2
Since function ‘ext4_getfsmap_find_fixed_metadata’ can be made static, make it so. Remove the following gcc warning (W=1): fs/ext4/fsmap.c:405:5: warning: no previous prototype for ‘ext4_getfsmap_find_fixed_metadata’ [-Wmissing-prototypes] Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-12-17ext4: fix up remaining files with SPDX cleanupsTheodore Ts'o1-14/+1
A number of ext4 source files were skipped due because their copyright permission statements didn't match the expected text used by the automated conversion utilities. I've added SPDX tags for the rest. While looking at some of these files, I've noticed that we have quite a bit of variation on the licenses that were used --- in particular some of the Red Hat licenses on the jbd2 files use a GPL2+ license, and we have some files that have a LGPL-2.1 license (which was quite surprising). I've not attempted to do any license changes. Even if it is perfectly legal to relicense to GPL 2.0-only for consistency's sake, that should be done with ext4 developer community discussion. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-23ext4: fix off-by-one fsmap error on 1k block filesystemsDarrick J. Wong1-0/+4
For 1k-block filesystems, the filesystem starts at block 1, not block 0. This fact is recorded in s_first_data_block, so use that to bump up the start_fsb before we start querying the filesystem for its space map. Without this, ext4/026 fails on 1k block ext4 because various functions (notably ext4_get_group_no_and_offset) don't know what to do with an fsblock that is "before" the start of the filesystem and return garbage results (blockgroup 2^32-1, etc.) that confuse fsmap. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-04-30ext4: support GETFSMAP ioctlsDarrick J. Wong1-0/+722
Support the GETFSMAP ioctls so that we can use the xfs free space management tools to probe ext4 as well. Note that this is a partial implementation -- we only report fixed-location metadata and free space; everything else is reported as "unknown". Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>