kernel.git/fs/ext4/extents.c, branch linux-3.14.y

ext4: check for extents that wrap around

2016-08-16T07:29:03Z

commit f70749ca42943faa4d4dcce46dfdcaadb1d0c4b6 upstream. An extent with lblock = 4294967295 and len = 1 will pass the ext4_valid_extent() test: ext4_lblk_t last = lblock + len - 1; if (len == 0 || lblock > last) return 0; since last = 4294967295 + 1 - 1 = 4294967295. This would later trigger the BUG_ON(es->es_lblk + es->es_len < es->es_lblk) in ext4_es_end(). We can simplify it by removing the - 1 altogether and changing the test to use lblock + len <= lblock, since now if len = 0, then lblock + 0 == lblock and it fails, and if len > 0 then lblock + len > lblock in order to pass (i.e. it doesn't overflow). Fixes: 5946d0893 ("ext4: check for overlapping extents in ext4_valid_extent_entries()") Fixes: 2f974865f ("ext4: check for zero length extent explicitly") Cc: Eryu Guan Signed-off-by: Phil Turnbull Signed-off-by: Vegard Nossum Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: verify extent header depth

2016-08-10T08:21:03Z

commit 7bc9491645118c9461bd21099c31755ff6783593 upstream. Although the extent tree depth of 5 should enough be for the worst case of 2*32 extents of length 1, the extent tree code does not currently to merge nodes which are less than half-full with a sibling node, or to shrink the tree depth if possible. So it's possible, at least in theory, for the tree depth to be greater than 5. However, even in the worst case, a tree depth of 32 is highly unlikely, and if the file system is maliciously corrupted, an insanely large eh_depth can cause memory allocation failures that will trigger kernel warnings (here, eh_depth = 65280): JBD2: ext4.exe wants too many credits credits:195849 rsv_credits:0 max:256 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 50 at fs/jbd2/transaction.c:293 start_this_handle+0x569/0x580 CPU: 0 PID: 50 Comm: ext4.exe Not tainted 4.7.0-rc5+ #508 Stack: 604a8947 625badd8 0002fd09 00000000 60078643 00000000 62623910 601bf9bc 62623970 6002fc84 626239b0 900000125 Call Trace: [<6001c2dc>] show_stack+0xdc/0x1a0 [<601bf9bc>] dump_stack+0x2a/0x2e [<6002fc84>] __warn+0x114/0x140 [<6002fdff>] warn_slowpath_null+0x1f/0x30 [<60165829>] start_this_handle+0x569/0x580 [<60165d4e>] jbd2__journal_start+0x11e/0x220 [<60146690>] __ext4_journal_start_sb+0x60/0xa0 [<60120a81>] ext4_truncate+0x131/0x3a0 [<60123677>] ext4_setattr+0x757/0x840 [<600d5d0f>] notify_change+0x16f/0x2a0 [<600b2b16>] do_truncate+0x76/0xc0 [<600c3e56>] path_openat+0x806/0x1300 [<600c55c9>] do_filp_open+0x89/0xf0 [<600b4074>] do_sys_open+0x134/0x1e0 [<600b4140>] SyS_open+0x20/0x30 [<6001ea68>] handle_syscall+0x88/0x90 [<600295fd>] userspace+0x3fd/0x500 [<6001ac55>] fork_handler+0x85/0x90 ---[ end trace 08b0b88b6387a244 ]--- [ Commit message modified and the extent tree depath check changed from 5 to 32 -- tytso ] Cc: Darrick J. Wong Signed-off-by: Vegard Nossum Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: check for zero length extent explicitly

2015-06-06T15:19:36Z

commit 2f974865ffdfe7b9f46a9940836c8b167342563d upstream. The following commit introduced a bug when checking for zero length extent 5946d08 ext4: check for overlapping extents in ext4_valid_extent_entries() Zero length extent could pass the check if lblock is zero. Adding the explicit check for zero length back. Signed-off-by: Eryu Guan Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: Replace open coded mdata csum feature to helper function

2014-11-14T16:59:58Z

commit 9aa5d32ba269bec0e7eaba2697a986a7b0bc8528 upstream. Besides the fact that this replacement improves code readability it also protects from errors caused direct EXT4_S(sb)->s_es manipulation which may result attempt to use uninitialized csum machinery. #Testcase_BEGIN IMG=/dev/ram0 MNT=/mnt mkfs.ext4 $IMG mount $IMG $MNT #Enable feature directly on disk, on mounted fs tune2fs -O metadata_csum $IMG # Provoke metadata update, likey result in OOPS touch $MNT/test umount $MNT #Testcase_END # Replacement script @@ expression E; @@ - EXT4_HAS_RO_COMPAT_FEATURE(E, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) + ext4_has_metadata_csum(E) https://bugzilla.kernel.org/show_bug.cgi?id=82201 Signed-off-by: Dmitry Monakhov Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

ext4: fix premature freeing of partial clusters split across leaf blocks

2014-04-27T00:19:06Z

commit ad6599ab3ac98a4474544086e048ce86ec15a4d1 upstream. Xfstests generic/311 and shared/298 fail when run on a bigalloc file system. Kernel error messages produced during the tests report that blocks to be freed are already on the to-be-freed list. When e2fsck is run at the end of the tests, it typically reports bad i_blocks and bad free blocks counts. The bug that causes these failures is located in ext4_ext_rm_leaf(). Code at the end of the function frees a partial cluster if it's not shared with an extent remaining in the leaf. However, if all the extents in the leaf have been removed, the code dereferences an invalid extent pointer (off the front of the leaf) when the check for sharing is made. This generally has the effect of unconditionally freeing the partial cluster, which leads to the observed failures when the partial cluster is shared with the last extent in the next leaf. Fix this by attempting to free the cluster only if extents remain in the leaf. Any remaining partial cluster will be freed if possible when the next leaf is processed or when leaf removal is complete. Signed-off-by: Eric Whitney Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: fix partial cluster handling for bigalloc file systems

2014-04-27T00:19:06Z

commit c06344939422bbd032ac967223a7863de57496b5 upstream. Commit 9cb00419fa, which enables hole punching for bigalloc file systems, exposed a bug introduced by commit 6ae06ff51e in an earlier release. When run on a bigalloc file system, xfstests generic/013, 068, 075, 083, 091, 100, 112, 127, 263, 269, and 270 fail with e2fsck errors or cause kernel error messages indicating that previously freed blocks are being freed again. The latter commit optimizes the selection of the starting extent in ext4_ext_rm_leaf() when hole punching by beginning with the extent supplied in the path argument rather than with the last extent in the leaf node (as is still done when truncating). However, the code in rm_leaf that initially sets partial_cluster to track cluster sharing on extent boundaries is only guaranteed to run if rm_leaf starts with the last node in the leaf. Consequently, partial_cluster is not correctly initialized when hole punching, and a cluster on the boundary of a punched region that should be retained may instead be deallocated. Signed-off-by: Eric Whitney Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: fix error return from ext4_ext_handle_uninitialized_extents()

2014-04-27T00:19:05Z

commit ce37c42919608e96ade3748fe23c3062a0a966c5 upstream. Commit 3779473246 breaks the return of error codes from ext4_ext_handle_uninitialized_extents() in ext4_ext_map_blocks(). A portion of the patch assigns that function's signed integer return value to an unsigned int. Consequently, negatively valued error codes are lost and can be treated as a bogus allocated block count. Signed-off-by: Eric Whitney Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: fix xfstest generic/299 block validity failures

2014-02-12T15:42:45Z

Commit a115f749c1 (ext4: remove wait for unwritten extent conversion from ext4_truncate) exposed a bug in ext4_ext_handle_uninitialized_extents(). It can be triggered by xfstest generic/299 when run on a test file system created without a journal. This test continuously fallocates and truncates files to which random dio/aio writes are simultaneously performed by a separate process. The test completes successfully, but if the test filesystem is mounted with the block_validity option, a warning message stating that a logical block has been mapped to an illegal physical block is posted in the kernel log. The bug occurs when an extent is being converted to the written state by ext4_end_io_dio() and ext4_ext_handle_uninitialized_extents() discovers a mapping for an existing uninitialized extent. Although it sets EXT4_MAP_MAPPED in map->m_flags, it fails to set map->m_pblk to the discovered physical block number. Because map->m_pblk is not otherwise initialized or set by this function or its callers, its uninitialized value is returned to ext4_map_blocks(), where it is stored as a bogus mapping in the extent status tree. Since map->m_pblk can accidentally contain illegal values that are larger than the physical size of the file system, calls to check_block_validity() in ext4_map_blocks() that are enabled if the block_validity mount option is used can fail, resulting in the logged warning message. Signed-off-by: Eric Whitney Signed-off-by: "Theodore Ts'o" Cc: stable@vger.kernel.org # 3.11+

ext4: fix a typo in extents.c

2014-01-06T19:05:23Z

Signed-off-by: Yongqiang Yang Reviewed-by: Carlos Maiolino

ext4: fix bigalloc regression

2014-01-06T19:00:23Z

Commit f5a44db5d2 introduced a regression on filesystems created with the bigalloc feature (cluster size > blocksize). It causes xfstests generic/006 and /013 to fail with an unexpected JBD2 failure and transaction abort that leaves the test file system in a read only state. Other xfstests run on bigalloc file systems are likely to fail as well. The cause is the accidental use of a cluster mask where a cluster offset was needed in ext4_ext_map_blocks(). Signed-off-by: Eric Whitney