kernel/linux.git/fs/ext4/ext4.h, branch v6.1.174

ext4: fix use-after-free in update_super_work when racing with umount

2026-04-11T12:16:34+00:00

[ Upstream commit d15e4b0a418537aafa56b2cb80d44add83e83697 ] Commit b98535d09179 ("ext4: fix bug_on in start_this_handle during umount filesystem") moved ext4_unregister_sysfs() before flushing s_sb_upd_work to prevent new error work from being queued via /proc/fs/ext4/xx/mb_groups reads during unmount. However, this introduced a use-after-free because update_super_work calls ext4_notify_error_sysfs() -> sysfs_notify() which accesses the kobject's kernfs_node after it has been freed by kobject_del() in ext4_unregister_sysfs(): update_super_work ext4_put_super ----------------- -------------- ext4_unregister_sysfs(sb) kobject_del(&sbi->s_kobj) __kobject_del() sysfs_remove_dir() kobj->sd = NULL sysfs_put(sd) kernfs_put() // RCU free ext4_notify_error_sysfs(sbi) sysfs_notify(&sbi->s_kobj) kn = kobj->sd // stale pointer kernfs_get(kn) // UAF on freed kernfs_node ext4_journal_destroy() flush_work(&sbi->s_sb_upd_work) Instead of reordering the teardown sequence, fix this by making ext4_notify_error_sysfs() detect that sysfs has already been torn down by checking s_kobj.state_in_sysfs, and skipping the sysfs_notify() call in that case. A dedicated mutex (s_error_notify_mutex) serializes ext4_notify_error_sysfs() against kobject_del() in ext4_unregister_sysfs() to prevent TOCTOU races where the kobject could be deleted between the state_in_sysfs check and the sysfs_notify() call. Fixes: b98535d09179 ("ext4: fix bug_on in start_this_handle during umount filesystem") Cc: Jiayuan Chen Suggested-by: Jan Kara Signed-off-by: Jiayuan Chen Reviewed-by: Ritesh Harjani (IBM) Reviewed-by: Jan Kara Link: https://patch.msgid.link/20260319120336.157873-1-jiayuan.chen@linux.dev Signed-off-by: Theodore Ts'o Cc: stable@kernel.org [ adapted mutex_init placement ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Revert "ext4: get rid of ppath in ext4_find_extent()"

2026-04-11T12:16:30+00:00

This reverts commit b5a010bc7dba7e3d0966c0231335ca76b3f8780e. Signed-off-by: Sasha Levin

Revert "ext4: get rid of ppath in ext4_ext_insert_extent()"

2026-04-11T12:16:30+00:00

This reverts commit b6a01b66cdaa2da526b512fc0f9938ea5d6c7a1c. Signed-off-by: Sasha Levin

ext4: get rid of ppath in ext4_ext_insert_extent()

2026-03-25T10:02:56+00:00

[ Upstream commit f7d1331f16a869c76a5102caebb58e840e1d509c ] The use of path and ppath is now very confusing, so to make the code more readable, pass path between functions uniformly, and get rid of ppath. To get rid of the ppath in ext4_ext_insert_extent(), the following is done here: * Free the extents path when an error is encountered. * Its caller needs to update ppath if it uses ppath. * Free path when npath is used, free npath when it is not used. * The got_allocated_blocks label in ext4_ext_map_blocks() does not update err now, so err is updated to 0 if the err returned by ext4_ext_search_right() is greater than 0 and is about to enter got_allocated_blocks. No functional changes. Signed-off-by: Baokun Li Reviewed-by: Jan Kara Reviewed-by: Ojaswin Mujoo Tested-by: Ojaswin Mujoo Link: https://patch.msgid.link/20240822023545.1994557-15-libaokun@huaweicloud.com Signed-off-by: Theodore Ts'o Stable-dep-of: 22784ca541c0 ("ext4: subdivide EXT4_EXT_DATA_VALID1") Signed-off-by: Sasha Levin

ext4: get rid of ppath in ext4_find_extent()

2026-03-25T10:02:55+00:00

[ Upstream commit 0be4c0c2f17bd10ae16c852f02d51a6a7b318aca ] The use of path and ppath is now very confusing, so to make the code more readable, pass path between functions uniformly, and get rid of ppath. Getting rid of ppath in ext4_find_extent() requires its caller to update ppath. These ppaths will also be dropped later. No functional changes. Signed-off-by: Baokun Li Reviewed-by: Jan Kara Reviewed-by: Ojaswin Mujoo Tested-by: Ojaswin Mujoo Link: https://patch.msgid.link/20240822023545.1994557-12-libaokun@huaweicloud.com Signed-off-by: Theodore Ts'o Stable-dep-of: 22784ca541c0 ("ext4: subdivide EXT4_EXT_DATA_VALID1") Signed-off-by: Sasha Levin

ext4: fix error message when rejecting the default hash

2026-01-11T14:19:26+00:00

commit a2187431c395cdfbf144e3536f25468c64fc7cfa upstream. Commit 985b67cd8639 ("ext4: filesystems without casefold feature cannot be mounted with siphash") properly rejects volumes where s_def_hash_version is set to DX_HASH_SIPHASH, but the check and the error message should not look into casefold setup - a filesystem should never have DX_HASH_SIPHASH as the default hash. Fix it and, since we are there, move the check to ext4_hash_info_init. Fixes:985b67cd8639 ("ext4: filesystems without casefold feature cannot be mounted with siphash") Signed-off-by: Gabriel Krisman Bertazi Link: https://patch.msgid.link/87jzg1en6j.fsf_-_@mailhost.krisman.be Signed-off-by: Theodore Ts'o Signed-off-by: Thadeu Lima de Souza Cascardo Signed-off-by: Greg Kroah-Hartman

ext4: fix checks for orphan inodes

2025-10-15T09:56:40+00:00

commit acf943e9768ec9d9be80982ca0ebc4bfd6b7631e upstream. When orphan file feature is enabled, inode can be tracked as orphan either in the standard orphan list or in the orphan file. The first can be tested by checking ei->i_orphan list head, the second is recorded by EXT4_STATE_ORPHAN_FILE inode state flag. There are several places where we want to check whether inode is tracked as orphan and only some of them properly check for both possibilities. Luckily the consequences are mostly minor, the worst that can happen is that we track an inode as orphan although we don't need to and e2fsck then complains (resulting in occasional ext4/307 xfstest failures). Fix the problem by introducing a helper for checking whether an inode is tracked as orphan and use it in appropriate places. Fixes: 4a79a98c7b19 ("ext4: Improve scalability of ext4 orphan file handling") Cc: stable@kernel.org Signed-off-by: Jan Kara Reviewed-by: Zhang Yi Message-ID: <20250925123038.20264-2-jack@suse.cz> Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

minmax: add in_range() macro

2025-10-02T11:40:41+00:00

[ Upstream commit f9bff0e31881d03badf191d3b0005839391f5f2b ] Patch series "New page table range API", v6. This patchset changes the API used by the MM to set up page table entries. The four APIs are: set_ptes(mm, addr, ptep, pte, nr) update_mmu_cache_range(vma, addr, ptep, nr) flush_dcache_folio(folio) flush_icache_pages(vma, page, nr) flush_dcache_folio() isn't technically new, but no architecture implemented it, so I've done that for them. The old APIs remain around but are mostly implemented by calling the new interfaces. The new APIs are based around setting up N page table entries at once. The N entries belong to the same PMD, the same folio and the same VMA, so ptep++ is a legitimate operation, and locking is taken care of for you. Some architectures can do a better job of it than just a loop, but I have hesitated to make too deep a change to architectures I don't understand well. One thing I have changed in every architecture is that PG_arch_1 is now a per-folio bit instead of a per-page bit when used for dcache clean/dirty tracking. This was something that would have to happen eventually, and it makes sense to do it now rather than iterate over every page involved in a cache flush and figure out if it needs to happen. The point of all this is better performance, and Fengwei Yin has measured improvement on x86. I suspect you'll see improvement on your architecture too. Try the new will-it-scale test mentioned here: https://lore.kernel.org/linux-mm/20230206140639.538867-5-fengwei.yin@intel.com/ You'll need to run it on an XFS filesystem and have CONFIG_TRANSPARENT_HUGEPAGE set. This patchset is the basis for much of the anonymous large folio work being done by Ryan, so it's received quite a lot of testing over the last few months. This patch (of 38): Determine if a value lies within a range more efficiently (subtraction + comparison vs two comparisons and an AND). It also has useful (under some circumstances) behaviour if the range exceeds the maximum value of the type. Convert all the conflicting definitions of in_range() within the kernel; some can use the generic definition while others need their own definition. Link: https://lkml.kernel.org/r/20230802151406.3735276-1-willy@infradead.org Link: https://lkml.kernel.org/r/20230802151406.3735276-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton Signed-off-by: Eliav Farber Signed-off-by: Greg Kroah-Hartman

ext4: factor out ext4_get_maxbytes()

2025-06-27T10:07:29+00:00

commit dbe27f06fa38b9bfc598f8864ae1c5d5831d9992 upstream. There are several locations that get the correct maxbytes value based on the inode's block type. It would be beneficial to extract a common helper function to make the code more clear. Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Reviewed-by: Baokun Li Link: https://patch.msgid.link/20250506012009.3896990-3-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

ext4: make 'abort' mount option handling standard

2024-12-14T18:53:14+00:00

[ Upstream commit 22b8d707b07e6e06f50fe1d9ca8756e1f894eb0d ] 'abort' mount option is the only mount option that has special handling and sets a bit in sbi->s_mount_flags. There is not strong reason for that so just simplify the code and make 'abort' set a bit in sbi->s_mount_opt2 as any other mount option. This simplifies the code and will allow us to drop EXT4_MF_FS_ABORTED completely in the following patch. Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230616165109.21695-4-jack@suse.cz Signed-off-by: Theodore Ts'o Stable-dep-of: 76486b104168 ("ext4: avoid remount errors with 'abort' mount option") Signed-off-by: Sasha Levin