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Filename Latest commit message Latest commit date
Baokun Li de8ada0236 ext4: prevent the normalized size from exceeding EXT_MAX_BLOCKS
commit 2dcf5fde6dffb312a4bfb8ef940cea2d1f402e32 upstream.

For files with logical blocks close to EXT_MAX_BLOCKS, the file size
predicted in ext4_mb_normalize_request() may exceed EXT_MAX_BLOCKS.
This can cause some blocks to be preallocated that will not be used.
And after [Fixes], the following issue may be triggered:

=========================================================
 kernel BUG at fs/ext4/mballoc.c:4653!
 Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
 CPU: 1 PID: 2357 Comm: xfs_io 6.7.0-rc2-00195-g0f5cc96c367f
 Hardware name: linux,dummy-virt (DT)
 pc : ext4_mb_use_inode_pa+0x148/0x208
 lr : ext4_mb_use_inode_pa+0x98/0x208
 Call trace:
  ext4_mb_use_inode_pa+0x148/0x208
  ext4_mb_new_inode_pa+0x240/0x4a8
  ext4_mb_use_best_found+0x1d4/0x208
  ext4_mb_try_best_found+0xc8/0x110
  ext4_mb_regular_allocator+0x11c/0xf48
  ext4_mb_new_blocks+0x790/0xaa8
  ext4_ext_map_blocks+0x7cc/0xd20
  ext4_map_blocks+0x170/0x600
  ext4_iomap_begin+0x1c0/0x348
=========================================================

Here is a calculation when adjusting ac_b_ex in ext4_mb_new_inode_pa():

	ex.fe_logical = orig_goal_end - EXT4_C2B(sbi, ex.fe_len);
	if (ac->ac_o_ex.fe_logical >= ex.fe_logical)
		goto adjust_bex;

The problem is that when orig_goal_end is subtracted from ac_b_ex.fe_len
it is still greater than EXT_MAX_BLOCKS, which causes ex.fe_logical to
overflow to a very small value, which ultimately triggers a BUG_ON in
ext4_mb_new_inode_pa() because pa->pa_free < len.

The last logical block of an actual write request does not exceed
EXT_MAX_BLOCKS, so in ext4_mb_normalize_request() also avoids normalizing
the last logical block to exceed EXT_MAX_BLOCKS to avoid the above issue.

The test case in [Link] can reproduce the above issue with 64k block size.

Link: https://patchwork.kernel.org/project/fstests/list/?series=804003
Cc:  <stable@kernel.org> # 6.4
Fixes: 93cdf49f6eca ("ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()")
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20231127063313.3734294-1-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-20 15:41:24 +01:00
arch KVM: s390/mm: Properly reset no-dat 2023-12-13 18:18:16 +01:00
block blk-throttle: fix lockdep warning of "cgroup_mutex or RCU read lock required!" 2023-12-20 15:41:20 +01:00
certs
crypto crypto: pcrypt - Fix hungtask for PADATA_RESET 2023-11-28 16:50:14 +00:00
Documentation firmware: ti_sci: Replace HTTP links with HTTPS ones 2023-11-20 10:30:12 +01:00
drivers soundwire: stream: fix NULL pointer dereference for multi_link 2023-12-20 15:41:24 +01:00
fs ext4: prevent the normalized size from exceeding EXT_MAX_BLOCKS 2023-12-20 15:41:24 +01:00
include asm-generic: qspinlock: fix queued_spin_value_unlocked() implementation 2023-12-20 15:41:22 +01:00
init x86/mm: Initialize text poking earlier 2023-08-08 19:56:36 +02:00
ipc
kernel perf: Fix perf_event_validate_size() lockdep splat 2023-12-20 15:41:23 +01:00
lib kobject: Fix slab-out-of-bounds in fill_kobj_path() 2023-11-08 11:23:38 +01:00
LICENSES
mm mm/cma: use nth_page() in place of direct struct page manipulation 2023-11-28 16:50:19 +00:00
net appletalk: Fix Use-After-Free in atalk_ioctl 2023-12-20 15:41:18 +01:00
samples
scripts sign-file: Fix incorrect return values check 2023-12-20 15:41:17 +01:00
security ima: detect changes to the backing overlay file 2023-12-08 08:44:27 +01:00
sound ALSA: hda/hdmi: add force-connect quirks for ASUSTeK Z170 variants 2023-12-20 15:41:19 +01:00
tools tools headers UAPI: Sync linux/perf_event.h with the kernel sources 2023-12-13 18:18:17 +01:00
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS iio: stx104: Move to addac subdirectory 2023-08-30 16:27:12 +02:00
Makefile Linux 5.4.264 2023-12-13 18:18:18 +01:00
README

Linux kernel
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There are several guides for kernel developers and users. These guides can
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    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
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