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CVE-2025-38337 – Linux Kernel jbd2 Data-Race and Null Pointer Dereference Vulnerability

The following table lists the changes that have been made to the
CVE-2025-38337 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution
of a vulnerability, and for identifying the most recent changes that may
impact the vulnerability’s severity, exploitability, or other characteristics.

  • New CVE Received
    by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jul. 10, 2025

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved:

    jbd2: fix data-race and null-ptr-deref in jbd2_journal_dirty_metadata()

    Since handle->h_transaction may be a NULL pointer, so we should change it
    to call is_handle_aborted(handle) first before dereferencing it.

    And the following data-race was reported in my fuzzer:

    ==================================================================
    BUG: KCSAN: data-race in jbd2_journal_dirty_metadata / jbd2_journal_dirty_metadata

    write to 0xffff888011024104 of 4 bytes by task 10881 on cpu 1:
    jbd2_journal_dirty_metadata+0x2a5/0x770 fs/jbd2/transaction.c:1556
    __ext4_handle_dirty_metadata+0xe7/0x4b0 fs/ext4/ext4_jbd2.c:358
    ext4_do_update_inode fs/ext4/inode.c:5220 [inline]
    ext4_mark_iloc_dirty+0x32c/0xd50 fs/ext4/inode.c:5869
    __ext4_mark_inode_dirty+0xe1/0x450 fs/ext4/inode.c:6074
    ext4_dirty_inode+0x98/0xc0 fs/ext4/inode.c:6103
    ….

    read to 0xffff888011024104 of 4 bytes by task 10880 on cpu 0:
    jbd2_journal_dirty_metadata+0xf2/0x770 fs/jbd2/transaction.c:1512
    __ext4_handle_dirty_metadata+0xe7/0x4b0 fs/ext4/ext4_jbd2.c:358
    ext4_do_update_inode fs/ext4/inode.c:5220 [inline]
    ext4_mark_iloc_dirty+0x32c/0xd50 fs/ext4/inode.c:5869
    __ext4_mark_inode_dirty+0xe1/0x450 fs/ext4/inode.c:6074
    ext4_dirty_inode+0x98/0xc0 fs/ext4/inode.c:6103
    ….

    value changed: 0x00000000 -> 0x00000001
    ==================================================================

    This issue is caused by missing data-race annotation for jh->b_modified.
    Therefore, the missing annotation needs to be added.
    Added Reference https://git.kernel.org/stable/c/23361b479f2700c00960d3ae9cdc8ededa762d47
    Added Reference https://git.kernel.org/stable/c/2e7c64d7a92c031d016f11c8e8cb05131ab7b75a
    Added Reference https://git.kernel.org/stable/c/43d5e3bb5f1dcd91e30238ea0b59a5f77063f84e
    Added Reference https://git.kernel.org/stable/c/5c1a34ff5b0bfdfd2f9343aa9b08d25df618bac5
    Added Reference https://git.kernel.org/stable/c/a377996d714afb8d4d5f4906336f78510039da29
    Added Reference https://git.kernel.org/stable/c/af98b0157adf6504fade79b3e6cb260c4ff68e37
    Added Reference https://git.kernel.org/stable/c/ec669e5bf409f16e464bfad75f0ba039a45de29a
    Added Reference https://git.kernel.org/stable/c/f78b38af3540b4875147b7b884ee11a27b3dbf4c
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