In the Linux kernel, the following vulnerability has been resolved: btrfs: do not ASSERT() when the fs flips RO inside btrfs_repair_io_failure() [BUG] There is a bug report that when btrfs hits ENOSPC error in a critical path, btrfs flips RO (this part is expected, although the ENOSPC bug still needs to be addressed). The problem is after the RO flip, if there is a read repair pending, we can hit the ASSERT() inside btrfs_repair_io_failure() like the following: BTRFS info (device vdc): relocating block group 30408704 flags metadata|raid1 ------------[ cut here ]------------ BTRFS: Transaction aborted (error -28) WARNING: fs/btrfs/extent-tree.c:3235 at __btrfs_free_extent.isra.0+0x453/0xfd0, CPU#1: btrfs/383844 Modules linked in: kvm_intel kvm irqbypass [...] ---[ end trace 0000000000000000 ]--- BTRFS info (device vdc state EA): 2 enospc errors during balance BTRFS info (device vdc state EA): balance: ended with status: -30 BTRFS error (device vdc state EA): parent transid verify failed on logical 30556160 mirror 2 wanted 8 found 6 BTRFS error (device vdc state EA): bdev /dev/nvme0n1 errs: wr 0, rd 0, flush 0, corrupt 10, gen 0 [...] assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938 ------------[ cut here ]------------ assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938 kernel BUG at fs/btrfs/bio.c:938! Oops: invalid opcode: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 868 Comm: kworker/u8:13 Tainted: G W N 6.19.0-rc6+ #4788 PREEMPT(full) Tainted: [W]=WARN, [N]=TEST Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 Workqueue: btrfs-endio simple_end_io_work RIP: 0010:btrfs_repair_io_failure.cold+0xb2/0x120 RSP: 0000:ffffc90001d2bcf0 EFLAGS: 00010246 RAX: 0000000000000051 RBX: 0000000000001000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8305cf42 RDI: 00000000ffffffff RBP: 0000000000000002 R08: 00000000fffeffff R09: ffffffff837fa988 R10: ffffffff8327a9e0 R11: 6f69747265737361 R12: ffff88813018d310 R13: ffff888168b8a000 R14: ffffc90001d2bd90 R15: ffff88810a169000 FS: 0000000000000000(0000) GS:ffff8885e752c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 ------------[ cut here ]------------ [CAUSE] The cause of -ENOSPC error during the test case btrfs/124 is still unknown, although it's known that we still have cases where metadata can be over-committed but can not be fulfilled correctly, thus if we hit such ENOSPC error inside a critical path, we have no choice but abort the current transaction. This will mark the fs read-only. The problem is inside the btrfs_repair_io_failure() path that we require the fs not to be mount read-only. This is normally fine, but if we are doing a read-repair meanwhile the fs flips RO due to a critical error, we can enter btrfs_repair_io_failure() with super block set to read-only, thus triggering the above crash. [FIX] Just replace the ASSERT() with a proper return if the fs is already read-only.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - In the Linux kernel, the following vulnerability has been resolved: btrfs: do not ASSERT() when the fs
    flips RO inside btrfs_repair_io_failure() [BUG] There is a bug report that when btrfs hits ENOSPC error in
    a critical path, btrfs flips RO (this part is expected, although the ENOSPC bug still needs to be
    addressed). The problem is after the RO flip, if there is a read repair pending, we can hit the ASSERT()
    inside btrfs_repair_io_failure() like the following: BTRFS info (device vdc): relocating block group
    30408704 flags metadata|raid1 ------------[ cut here ]------------ BTRFS: Transaction aborted (error -28)
    WARNING: fs/btrfs/extent-tree.c:3235 at __btrfs_free_extent.isra.0+0x453/0xfd0, CPU#1: btrfs/383844
    Modules linked in: kvm_intel kvm irqbypass [...] ---[ end trace 0000000000000000 ]--- BTRFS info (device
    vdc state EA): 2 enospc errors during balance BTRFS info (device vdc state EA): balance: ended with
    status: -30 BTRFS error (device vdc state EA): parent transid verify failed on logical 30556160 mirror 2
    wanted 8 found 6 BTRFS error (device vdc state EA): bdev /dev/nvme0n1 errs: wr 0, rd 0, flush 0, corrupt
    10, gen 0 [...] assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938
    ------------[ cut here ]------------ assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in
    fs/btrfs/bio.c:938 kernel BUG at fs/btrfs/bio.c:938! Oops: invalid opcode: 0000 [#1] SMP NOPTI CPU: 0 UID:
    0 PID: 868 Comm: kworker/u8:13 Tainted: G W N 6.19.0-rc6+ #4788 PREEMPT(full) Tainted: [W]=WARN, [N]=TEST
    Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org
    04/01/2014 Workqueue: btrfs-endio simple_end_io_work RIP: 0010:btrfs_repair_io_failure.cold+0xb2/0x120
    RSP: 0000:ffffc90001d2bcf0 EFLAGS: 00010246 RAX: 0000000000000051 RBX: 0000000000001000 RCX:
    0000000000000000 RDX: 0000000000000000 RSI: ffffffff8305cf42 RDI: 00000000ffffffff RBP: 0000000000000002
    R08: 00000000fffeffff R09: ffffffff837fa988 R10: ffffffff8327a9e0 R11: 6f69747265737361 R12:
    ffff88813018d310 R13: ffff888168b8a000 R14: ffffc90001d2bd90 R15: ffff88810a169000 FS:
    0000000000000000(0000) GS:ffff8885e752c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0:
    0000000080050033 ------------[ cut here ]------------ [CAUSE] The cause of -ENOSPC error during the test
    case btrfs/124 is still unknown, although it's known that we still have cases where metadata can be over-
    committed but can not be fulfilled correctly, thus if we hit such ENOSPC error inside a critical path, we
    have no choice but abort the current transaction. This will mark the fs read-only. The problem is inside
    the btrfs_repair_io_failure() path that we require the fs not to be mount read-only. This is normally
    fine, but if we are doing a read-repair meanwhile the fs flips RO due to a critical error, we can enter
    btrfs_repair_io_failure() with super block set to read-only, thus triggering the above crash. [FIX] Just
    replace the ASSERT() with a proper return if the fs is already read-only. (CVE-2026-43299)

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-098805 advisory.

    In the Linux kernel, the following vulnerability has been resolved:

    btrfs: do not ASSERT() when the fs flips RO inside btrfs_repair_io_failure()

    [BUG]     There is a bug report that when btrfs hits ENOSPC error in a critical     path, btrfs flips RO (this part is expected, although the ENOSPC bug     still needs to be addressed).

    The problem is after the RO flip, if there is a read repair pending, we     can hit the ASSERT() inside btrfs_repair_io_failure() like the following:

      BTRFS info (device vdc): relocating block group 30408704 flags metadata|raid1
      ------------[ cut here ]------------       BTRFS: Transaction aborted (error -28)       WARNING: fs/btrfs/extent-tree.c:3235 at __btrfs_free_extent.isra.0+0x453/0xfd0, CPU#1: btrfs/383844       Modules linked in: kvm_intel kvm irqbypass       [...]
      ---[ end trace 0000000000000000 ]---       BTRFS info (device vdc state EA): 2 enospc errors during balance       BTRFS info (device vdc state EA): balance: ended with status: -30       BTRFS error (device vdc state EA): parent transid verify failed on logical 30556160 mirror 2 wanted 8     found 6       BTRFS error (device vdc state EA): bdev /dev/nvme0n1 errs: wr 0, rd 0, flush 0, corrupt 10, gen 0       [...]       assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938
      ------------[ cut here ]------------       assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938       kernel BUG at fs/btrfs/bio.c:938!       Oops: invalid opcode: 0000 [#1] SMP NOPTI       CPU: 0 UID: 0 PID: 868 Comm: kworker/u8:13 Tainted: G        W        N  6.19.0-rc6+ #4788 PREEMPT(full)       Tainted: [W]=WARN, [N]=TEST       Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org     04/01/2014       Workqueue: btrfs-endio simple_end_io_work       RIP: 0010:btrfs_repair_io_failure.cold+0xb2/0x120       RSP: 0000:ffffc90001d2bcf0 EFLAGS: 00010246       RAX: 0000000000000051 RBX: 0000000000001000 RCX: 0000000000000000       RDX: 0000000000000000 RSI: ffffffff8305cf42 RDI: 00000000ffffffff       RBP: 0000000000000002 R08: 00000000fffeffff R09: ffffffff837fa988       R10: ffffffff8327a9e0 R11: 6f69747265737361 R12: ffff88813018d310       R13: ffff888168b8a000 R14: ffffc90001d2bd90 R15: ffff88810a169000       FS:  0000000000000000(0000) GS:ffff8885e752c000(0000) knlGS:0000000000000000       CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      ------------[ cut here ]------------

    [CAUSE]     The cause of -ENOSPC error during the test case btrfs/124 is still     unknown, although it's known that we still have cases where metadata can     be over-committed but can not be fulfilled correctly, thus if we hit     such ENOSPC error inside a critical path, we have no choice but abort     the current transaction.

    This will mark the fs read-only.

    The problem is inside the btrfs_repair_io_failure() path that we require     the fs not to be mount read-only. This is normally fine, but if we are     doing a read-repair meanwhile the fs flips RO due to a critical error,     we can enter btrfs_repair_io_failure() with super block set to     read-only, thus triggering the above crash.

    [FIX]     Just replace the ASSERT() with a proper return if the fs is already     read-only.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-102111 advisory.

    In the Linux kernel, the following vulnerability has been resolved:

    btrfs: do not ASSERT() when the fs flips RO inside btrfs_repair_io_failure()

    [BUG]     There is a bug report that when btrfs hits ENOSPC error in a critical     path, btrfs flips RO (this part is expected, although the ENOSPC bug     still needs to be addressed).

    The problem is after the RO flip, if there is a read repair pending, we     can hit the ASSERT() inside btrfs_repair_io_failure() like the following:

      BTRFS info (device vdc): relocating block group 30408704 flags metadata|raid1
      ------------[ cut here ]------------       BTRFS: Transaction aborted (error -28)       WARNING: fs/btrfs/extent-tree.c:3235 at __btrfs_free_extent.isra.0+0x453/0xfd0, CPU#1: btrfs/383844       Modules linked in: kvm_intel kvm irqbypass       [...]
      ---[ end trace 0000000000000000 ]---       BTRFS info (device vdc state EA): 2 enospc errors during balance       BTRFS info (device vdc state EA): balance: ended with status: -30       BTRFS error (device vdc state EA): parent transid verify failed on logical 30556160 mirror 2 wanted 8     found 6       BTRFS error (device vdc state EA): bdev /dev/nvme0n1 errs: wr 0, rd 0, flush 0, corrupt 10, gen 0       [...]       assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938
      ------------[ cut here ]------------       assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938       kernel BUG at fs/btrfs/bio.c:938!       Oops: invalid opcode: 0000 [#1] SMP NOPTI       CPU: 0 UID: 0 PID: 868 Comm: kworker/u8:13 Tainted: G        W        N  6.19.0-rc6+ #4788 PREEMPT(full)       Tainted: [W]=WARN, [N]=TEST       Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org     04/01/2014       Workqueue: btrfs-endio simple_end_io_work       RIP: 0010:btrfs_repair_io_failure.cold+0xb2/0x120       RSP: 0000:ffffc90001d2bcf0 EFLAGS: 00010246       RAX: 0000000000000051 RBX: 0000000000001000 RCX: 0000000000000000       RDX: 0000000000000000 RSI: ffffffff8305cf42 RDI: 00000000ffffffff       RBP: 0000000000000002 R08: 00000000fffeffff R09: ffffffff837fa988       R10: ffffffff8327a9e0 R11: 6f69747265737361 R12: ffff88813018d310       R13: ffff888168b8a000 R14: ffffc90001d2bd90 R15: ffff88810a169000       FS:  0000000000000000(0000) GS:ffff8885e752c000(0000) knlGS:0000000000000000       CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      ------------[ cut here ]------------

    [CAUSE]     The cause of -ENOSPC error during the test case btrfs/124 is still     unknown, although it's known that we still have cases where metadata can     be over-committed but can not be fulfilled correctly, thus if we hit     such ENOSPC error inside a critical path, we have no choice but abort     the current transaction.

    This will mark the fs read-only.

    The problem is inside the btrfs_repair_io_failure() path that we require     the fs not to be mount read-only. This is normally fine, but if we are     doing a read-repair meanwhile the fs flips RO due to a critical error,     we can enter btrfs_repair_io_failure() with super block set to     read-only, thus triggering the above crash.

    [FIX]     Just replace the ASSERT() with a proper return if the fs is already     read-only.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - btrfs: do not ASSERT() when the fs flips RO inside btrfs_repair_io_failure() [BUG] There is a bug report     that when btrfs hits ENOSPC error in a critical path, btrfs flips RO (this part is expected, although the     ENOSPC bug still needs to be addressed). The problem is after the RO flip, if there is a read repair     pending, we can hit the ASSERT() inside btrfs_repair_io_failure() like the following: BTRFS info (device     vdc): relocating block group 30408704 flags metadata|raid1 ------------[ cut here ]------------ BTRFS:
    Transaction aborted (error -28) WARNING: fs/btrfs/extent-tree.c:3235 at
    __btrfs_free_extent.isra.0+0x453/0xfd0, CPU#1: btrfs/383844 Modules linked in: kvm_intel kvm irqbypass     [...] ---[ end trace 0000000000000000 ]--- BTRFS info (device vdc state EA): 2 enospc errors during     balance BTRFS info (device vdc state EA): balance: ended with status: -30 BTRFS error (device vdc state     EA): parent transid verify failed on logical 30556160 mirror 2 wanted 8 found 6 BTRFS error (device vdc     state EA): bdev /dev/nvme0n1 errs: wr 0, rd 0, flush 0, corrupt 10, gen 0 [...] assertion failed:
    !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938 ------------[ cut here ]------------     assertion failed: !(fs_info->sb->s_flags & SB_RDONLY) :: 0, in fs/btrfs/bio.c:938 kernel BUG at     fs/btrfs/bio.c:938! Oops: invalid opcode: 0000 [#1] SMP NOPTI CPU: 0 UID: 0 PID: 868 Comm: kworker/u8:13     Tainted: G W N 6.19.0-rc6+ #4788 PREEMPT(full) Tainted: [W]=WARN, [N]=TEST Hardware name: QEMU Standard PC     (Q35 + ICH9, 2009), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 Workqueue: btrfs-endio     simple_end_io_work RIP: 0010:btrfs_repair_io_failure.cold+0xb2/0x120 RSP: 0000:ffffc90001d2bcf0 EFLAGS:
    00010246 RAX: 0000000000000051 RBX: 0000000000001000 RCX: 0000000000000000 RDX: 0000000000000000 RSI:
    ffffffff8305cf42 RDI: 00000000ffffffff RBP: 0000000000000002 R08: 00000000fffeffff R09: ffffffff837fa988     R10: ffffffff8327a9e0 R11: 6f69747265737361 R12: ffff88813018d310 R13: ffff888168b8a000 R14:
    ffffc90001d2bd90 R15: ffff88810a169000 FS: 0000000000000000(0000) GS:ffff8885e752c000(0000)     knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 ------------[ cut here     ]------------ [CAUSE] The cause of -ENOSPC error during the test case btrfs/124 is still unknown, although     it's known that we still have cases where metadata can be over-committed but can not be fulfilled     correctly, thus if we hit such ENOSPC error inside a critical path, we have no choice but abort the     current transaction. This will mark the fs read-only. The problem is inside the btrfs_repair_io_failure()     path that we require the fs not to be mount read-only. This is normally fine, but if we are doing a read-     repair meanwhile the fs flips RO due to a critical error, we can enter btrfs_repair_io_failure() with     super block set to read-only, thus triggering the above crash. [FIX] Just replace the ASSERT() with a     proper return if the fs is already read-only. (CVE-2026-43299)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
472554	Chainguard: linux-qemu-melange: security update to 6.18.49-r2	Tenable Cloud Security	Chainguard Local Security Checks	Local	medium
472554	Chainguard: linux-qemu-melange: security update to 6.18.49-r2	Tenable Self-Hosted Container Security	Chainguard Local Security Checks	Local	medium
350138	openSUSE 16: cluster-md-kmp-64kb / cluster-md-kmp-azure / cluster-md-kmp-default / etc (openSUSE-SU-2026:21910-1)	Nessus	SuSE Local Security Checks	Local	high
340429	Unity Linux 20.1050a Security Update: kernel (UTSA-2026-098805)	Nessus	Unity Linux Local Security Checks	Local	medium
337325	Unity Linux 20.1050e Security Update: kernel (UTSA-2026-102111)	Nessus	Unity Linux Local Security Checks	Local	medium
313384	Linux Distros Unpatched Vulnerability : CVE-2026-43299	Nessus	Misc.	Local	medium

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