linux-stable.git/fs/ext4, branch v5.4.280

ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find()

2024-06-16T11:28:52+00:00

commit 0c0b4a49d3e7f49690a6827a41faeffad5df7e21 upstream.

Syzbot reports a warning as follows:

============================================
WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290
Modules linked in:
CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7
RIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419
Call Trace:
 
 ext4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375
 generic_shutdown_super+0x136/0x2d0 fs/super.c:641
 kill_block_super+0x44/0x90 fs/super.c:1675
 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327
[...]
============================================

This is because when finding an entry in ext4_xattr_block_cache_find(), if
ext4_sb_bread() returns -ENOMEM, the ce's e_refcnt, which has already grown
in the __entry_find(), won't be put away, and eventually trigger the above
issue in mb_cache_destroy() due to reference count leakage.

So call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix.

Reported-by: syzbot+dd43bd0f7474512edc47@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=dd43bd0f7474512edc47
Fixes: fb265c9cb49e ("ext4: add ext4_sb_bread() to disambiguate ENOMEM cases")
Cc: stable@kernel.org
Signed-off-by: Baokun Li 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20240504075526.2254349-2-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: avoid excessive credit estimate in ext4_tmpfile()

2024-06-16T11:28:40+00:00

[ Upstream commit 35a1f12f0ca857fee1d7a04ef52cbd5f1f84de13 ]

A user with minimum journal size (1024 blocks these days) complained
about the following error triggered by generic/697 test in
ext4_tmpfile():

run fstests generic/697 at 2024-02-28 05:34:46
JBD2: vfstest wants too many credits credits:260 rsv_credits:0 max:256
EXT4-fs error (device loop0) in __ext4_new_inode:1083: error 28

Indeed the credit estimate in ext4_tmpfile() is huge.
EXT4_MAXQUOTAS_INIT_BLOCKS() is 219, then 10 credits from ext4_tmpfile()
itself and then ext4_xattr_credits_for_new_inode() adds more credits
needed for security attributes and ACLs. Now the
EXT4_MAXQUOTAS_INIT_BLOCKS() is in fact unnecessary because we've
already initialized quotas with dquot_init() shortly before and so
EXT4_MAXQUOTAS_TRANS_BLOCKS() is enough (which boils down to 3 credits).

Fixes: af51a2ac36d1 ("ext4: ->tmpfile() support")
Signed-off-by: Jan Kara 
Tested-by: Luis Henriques 
Tested-by: Disha Goel 
Link: https://lore.kernel.org/r/20240307115320.28949-1-jack@suse.cz
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ext4: fix bug_on in __es_tree_search

2024-05-25T14:17:16+00:00

commit d36f6ed761b53933b0b4126486c10d3da7751e7f upstream.

Hulk Robot reported a BUG_ON:
==================================================================
kernel BUG at fs/ext4/extents_status.c:199!
[...]
RIP: 0010:ext4_es_end fs/ext4/extents_status.c:199 [inline]
RIP: 0010:__es_tree_search+0x1e0/0x260 fs/ext4/extents_status.c:217
[...]
Call Trace:
 ext4_es_cache_extent+0x109/0x340 fs/ext4/extents_status.c:766
 ext4_cache_extents+0x239/0x2e0 fs/ext4/extents.c:561
 ext4_find_extent+0x6b7/0xa20 fs/ext4/extents.c:964
 ext4_ext_map_blocks+0x16b/0x4b70 fs/ext4/extents.c:4384
 ext4_map_blocks+0xe26/0x19f0 fs/ext4/inode.c:567
 ext4_getblk+0x320/0x4c0 fs/ext4/inode.c:980
 ext4_bread+0x2d/0x170 fs/ext4/inode.c:1031
 ext4_quota_read+0x248/0x320 fs/ext4/super.c:6257
 v2_read_header+0x78/0x110 fs/quota/quota_v2.c:63
 v2_check_quota_file+0x76/0x230 fs/quota/quota_v2.c:82
 vfs_load_quota_inode+0x5d1/0x1530 fs/quota/dquot.c:2368
 dquot_enable+0x28a/0x330 fs/quota/dquot.c:2490
 ext4_quota_enable fs/ext4/super.c:6137 [inline]
 ext4_enable_quotas+0x5d7/0x960 fs/ext4/super.c:6163
 ext4_fill_super+0xa7c9/0xdc00 fs/ext4/super.c:4754
 mount_bdev+0x2e9/0x3b0 fs/super.c:1158
 mount_fs+0x4b/0x1e4 fs/super.c:1261
[...]
==================================================================

Above issue may happen as follows:
-------------------------------------
ext4_fill_super
 ext4_enable_quotas
  ext4_quota_enable
   ext4_iget
    __ext4_iget
     ext4_ext_check_inode
      ext4_ext_check
       __ext4_ext_check
        ext4_valid_extent_entries
         Check for overlapping extents does't take effect
   dquot_enable
    vfs_load_quota_inode
     v2_check_quota_file
      v2_read_header
       ext4_quota_read
        ext4_bread
         ext4_getblk
          ext4_map_blocks
           ext4_ext_map_blocks
            ext4_find_extent
             ext4_cache_extents
              ext4_es_cache_extent
               ext4_es_cache_extent
                __es_tree_search
                 ext4_es_end
                  BUG_ON(es->es_lblk + es->es_len < es->es_lblk)

The error ext4 extents is as follows:
0af3 0300 0400 0000 00000000    extent_header
00000000 0100 0000 12000000     extent1
00000000 0100 0000 18000000     extent2
02000000 0400 0000 14000000     extent3

In the ext4_valid_extent_entries function,
if prev is 0, no error is returned even if lblock<=prev.
This was intended to skip the check on the first extent, but
in the error image above, prev=0+1-1=0 when checking the second extent,
so even though lblock<=prev, the function does not return an error.
As a result, bug_ON occurs in __es_tree_search and the system panics.

To solve this problem, we only need to check that:
1. The lblock of the first extent is not less than 0.
2. The lblock of the next extent  is not less than
   the next block of the previous extent.
The same applies to extent_idx.

Cc: stable@kernel.org
Fixes: 5946d089379a ("ext4: check for overlapping extents in ext4_valid_extent_entries()")
Reported-by: Hulk Robot 
Signed-off-by: Baokun Li 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20220518120816.1541863-1-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o 
Reported-by: syzbot+2a58d88f0fb315c85363@syzkaller.appspotmail.com
[gpiccoli: Manual backport due to unrelated missing patches.]
Signed-off-by: Guilherme G. Piccoli 
Signed-off-by: Greg Kroah-Hartman

ext4: fix corruption during on-line resize

2024-04-13T10:51:26+00:00

[ Upstream commit a6b3bfe176e8a5b05ec4447404e412c2a3fc92cc ]

We observed a corruption during on-line resize of a file system that is
larger than 16 TiB with 4k block size. With having more then 2^32 blocks
resize_inode is turned off by default by mke2fs. The issue can be
reproduced on a smaller file system for convenience by explicitly
turning off resize_inode. An on-line resize across an 8 GiB boundary (the
size of a meta block group in this setup) then leads to a corruption:

  dev=/dev/ # should be >= 16 GiB
  mkdir -p /corruption
  /sbin/mke2fs -t ext4 -b 4096 -O ^resize_inode $dev $((2 * 2**21 - 2**15))
  mount -t ext4 $dev /corruption

  dd if=/dev/zero bs=4096 of=/corruption/test count=$((2*2**21 - 4*2**15))
  sha1sum /corruption/test
  # 79d2658b39dcfd77274e435b0934028adafaab11  /corruption/test

  /sbin/resize2fs $dev $((2*2**21))
  # drop page cache to force reload the block from disk
  echo 1 > /proc/sys/vm/drop_caches

  sha1sum /corruption/test
  # 3c2abc63cbf1a94c9e6977e0fbd72cd832c4d5c3  /corruption/test

2^21 = 2^15*2^6 equals 8 GiB whereof 2^15 is the number of blocks per
block group and 2^6 are the number of block groups that make a meta
block group.

The last checksum might be different depending on how the file is laid
out across the physical blocks. The actual corruption occurs at physical
block 63*2^15 = 2064384 which would be the location of the backup of the
meta block group's block descriptor. During the on-line resize the file
system will be converted to meta_bg starting at s_first_meta_bg which is
2 in the example - meaning all block groups after 16 GiB. However, in
ext4_flex_group_add we might add block groups that are not part of the
first meta block group yet. In the reproducer we achieved this by
substracting the size of a whole block group from the point where the
meta block group would start. This must be considered when updating the
backup block group descriptors to follow the non-meta_bg layout. The fix
is to add a test whether the group to add is already part of the meta
block group or not.

Fixes: 01f795f9e0d67 ("ext4: add online resizing support for meta_bg and 64-bit file systems")
Cc:  
Signed-off-by: Maximilian Heyne 
Tested-by: Srivathsa Dara 
Reviewed-by: Srivathsa Dara 
Link: https://lore.kernel.org/r/20240215155009.94493-1-mheyne@amazon.de
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ext4: correct best extent lstart adjustment logic

2024-04-13T10:51:23+00:00

[ Upstream commit 4fbf8bc733d14bceb16dda46a3f5e19c6a9621c5 ]

When yangerkun review commit 93cdf49f6eca ("ext4: Fix best extent lstart
adjustment logic in ext4_mb_new_inode_pa()"), it was found that the best
extent did not completely cover the original request after adjusting the
best extent lstart in ext4_mb_new_inode_pa() as follows:

  original request: 2/10(8)
  normalized request: 0/64(64)
  best extent: 0/9(9)

When we check if best ex can be kept at start of goal, ac_o_ex.fe_logical
is 2 less than the adjusted best extent logical end 9, so we think the
adjustment is done. But obviously 0/9(9) doesn't cover 2/10(8), so we
should determine here if the original request logical end is less than or
equal to the adjusted best extent logical end.

In addition, add a comment stating when adjusted best_ex will not cover
the original request, and remove the duplicate assertion because adjusting
lstart makes no change to b_ex.fe_len.

Link: https://lore.kernel.org/r/3630fa7f-b432-7afd-5f79-781bc3b2c5ea@huawei.com
Fixes: 93cdf49f6eca ("ext4: Fix best extent lstart adjustment logic in ext4_mb_new_inode_pa()")
Cc:  
Signed-off-by: yangerkun 
Signed-off-by: Baokun Li 
Reviewed-by: Jan Kara 
Reviewed-by: Ojaswin Mujoo 
Link: https://lore.kernel.org/r/20240201141845.1879253-1-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ext4: avoid allocating blocks from corrupted group in ext4_mb_find_by_goal()

2024-03-01T12:13:33+00:00

[ Upstream commit 832698373a25950942c04a512daa652c18a9b513 ]

Places the logic for checking if the group's block bitmap is corrupt under
the protection of the group lock to avoid allocating blocks from the group
with a corrupted block bitmap.

Signed-off-by: Baokun Li 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20240104142040.2835097-8-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ext4: avoid allocating blocks from corrupted group in ext4_mb_try_best_found()

2024-03-01T12:13:33+00:00

[ Upstream commit 4530b3660d396a646aad91a787b6ab37cf604b53 ]

Determine if the group block bitmap is corrupted before using ac_b_ex in
ext4_mb_try_best_found() to avoid allocating blocks from a group with a
corrupted block bitmap in the following concurrency and making the
situation worse.

ext4_mb_regular_allocator
  ext4_lock_group(sb, group)
  ext4_mb_good_group
   // check if the group bbitmap is corrupted
  ext4_mb_complex_scan_group
   // Scan group gets ac_b_ex but doesn't use it
  ext4_unlock_group(sb, group)
                           ext4_mark_group_bitmap_corrupted(group)
                           // The block bitmap was corrupted during
                           // the group unlock gap.
  ext4_mb_try_best_found
    ext4_lock_group(ac->ac_sb, group)
    ext4_mb_use_best_found
      mb_mark_used
      // Allocating blocks in block bitmap corrupted group

Signed-off-by: Baokun Li 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20240104142040.2835097-7-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ext4: fix double-free of blocks due to wrong extents moved_len

2024-02-23T07:25:11+00:00

commit 55583e899a5357308274601364741a83e78d6ac4 upstream.

In ext4_move_extents(), moved_len is only updated when all moves are
successfully executed, and only discards orig_inode and donor_inode
preallocations when moved_len is not zero. When the loop fails to exit
after successfully moving some extents, moved_len is not updated and
remains at 0, so it does not discard the preallocations.

If the moved extents overlap with the preallocated extents, the
overlapped extents are freed twice in ext4_mb_release_inode_pa() and
ext4_process_freed_data() (as described in commit 94d7c16cbbbd ("ext4:
Fix double-free of blocks with EXT4_IOC_MOVE_EXT")), and bb_free is
incremented twice. Hence when trim is executed, a zero-division bug is
triggered in mb_update_avg_fragment_size() because bb_free is not zero
and bb_fragments is zero.

Therefore, update move_len after each extent move to avoid the issue.

Reported-by: Wei Chen 
Reported-by: xingwei lee 
Closes: https://lore.kernel.org/r/CAO4mrferzqBUnCag8R3m2zf897ts9UEuhjFQGPtODT92rYyR2Q@mail.gmail.com
Fixes: fcf6b1b729bc ("ext4: refactor ext4_move_extents code base")
CC:   # 3.18
Signed-off-by: Baokun Li 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20240104142040.2835097-2-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: avoid online resizing failures due to oversized flex bg

2024-02-23T07:24:56+00:00

[ Upstream commit 5d1935ac02ca5aee364a449a35e2977ea84509b0 ]

When we online resize an ext4 filesystem with a oversized flexbg_size,

     mkfs.ext4 -F -G 67108864 $dev -b 4096 100M
     mount $dev $dir
     resize2fs $dev 16G

the following WARN_ON is triggered:
==================================================================
WARNING: CPU: 0 PID: 427 at mm/page_alloc.c:4402 __alloc_pages+0x411/0x550
Modules linked in: sg(E)
CPU: 0 PID: 427 Comm: resize2fs Tainted: G  E  6.6.0-rc5+ #314
RIP: 0010:__alloc_pages+0x411/0x550
Call Trace:
 
 __kmalloc_large_node+0xa2/0x200
 __kmalloc+0x16e/0x290
 ext4_resize_fs+0x481/0xd80
 __ext4_ioctl+0x1616/0x1d90
 ext4_ioctl+0x12/0x20
 __x64_sys_ioctl+0xf0/0x150
 do_syscall_64+0x3b/0x90
==================================================================

This is because flexbg_size is too large and the size of the new_group_data
array to be allocated exceeds MAX_ORDER. Currently, the minimum value of
MAX_ORDER is 8, the minimum value of PAGE_SIZE is 4096, the corresponding
maximum number of groups that can be allocated is:

 (PAGE_SIZE << MAX_ORDER) / sizeof(struct ext4_new_group_data) ≈ 21845

And the value that is down-aligned to the power of 2 is 16384. Therefore,
this value is defined as MAX_RESIZE_BG, and the number of groups added
each time does not exceed this value during resizing, and is added multiple
times to complete the online resizing. The difference is that the metadata
in a flex_bg may be more dispersed.

Signed-off-by: Baokun Li 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20231023013057.2117948-4-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin

ext4: remove unnecessary check from alloc_flex_gd()

2024-02-23T07:24:56+00:00

[ Upstream commit b099eb87de105cf07cad731ded6fb40b2675108b ]

In commit 967ac8af4475 ("ext4: fix potential integer overflow in
alloc_flex_gd()"), an overflow check is added to alloc_flex_gd() to
prevent the allocated memory from being smaller than expected due to
the overflow. However, after kmalloc() is replaced with kmalloc_array()
in commit 6da2ec56059c ("treewide: kmalloc() -> kmalloc_array()"), the
kmalloc_array() function has an overflow check, so the above problem
will not occur. Therefore, the extra check is removed.

Signed-off-by: Baokun Li 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20231023013057.2117948-3-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Sasha Levin