CVE-2026-43237

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Refactor amdgpu_gem_va_ioctl for Handling Last Fence Update and Timeline Management v4 This commit simplifies the amdgpu_gem_va_ioctl function, key updates include: - Moved the logic for managing the last update fence directly into amdgpu_gem_va_update_vm. - Introduced checks for the timeline point to enable conditional replacement or addition of fences. v2: Addressed review comments from Christian. v3: Updated comments (Christian). v4: The previous version selected the fence too early and did not manage its reference correctly, which could lead to stale or freed fences being used. This resulted in refcount underflows and could crash when updating GPU timelines. The fence is now chosen only after the VA mapping work is completed, and its reference is taken safely. After exporting it to the VM timeline syncobj, the driver always drops its local fence reference, ensuring balanced refcounting and avoiding use-after-free on dma_fence. Crash signature: [ 205.828135] refcount_t: underflow; use-after-free. [ 205.832963] WARNING: CPU: 30 PID: 7274 at lib/refcount.c:28 refcount_warn_saturate+0xbe/0x110 ... [ 206.074014] Call Trace: [ 206.076488] <TASK> [ 206.078608] amdgpu_gem_va_ioctl+0x6ea/0x740 [amdgpu] [ 206.084040] ? __pfx_amdgpu_gem_va_ioctl+0x10/0x10 [amdgpu] [ 206.089994] drm_ioctl_kernel+0x86/0xe0 [drm] [ 206.094415] drm_ioctl+0x26e/0x520 [drm] [ 206.098424] ? __pfx_amdgpu_gem_va_ioctl+0x10/0x10 [amdgpu] [ 206.104402] amdgpu_drm_ioctl+0x4b/0x80 [amdgpu] [ 206.109387] __x64_sys_ioctl+0x96/0xe0 [ 206.113156] do_syscall_64+0x66/0x2d0 ... [ 206.553351] BUG: unable to handle page fault for address: ffffffffc0dfde90 ... [ 206.553378] RIP: 0010:dma_fence_signal_timestamp_locked+0x39/0xe0 ... [ 206.553405] Call Trace: [ 206.553409] <IRQ> [ 206.553415] ? __pfx_drm_sched_fence_free_rcu+0x10/0x10 [gpu_sched] [ 206.553424] dma_fence_signal+0x30/0x60 [ 206.553427] drm_sched_job_done.isra.0+0x123/0x150 [gpu_sched] [ 206.553434] dma_fence_signal_timestamp_locked+0x6e/0xe0 [ 206.553437] dma_fence_signal+0x30/0x60 [ 206.553441] amdgpu_fence_process+0xd8/0x150 [amdgpu] [ 206.553854] sdma_v4_0_process_trap_irq+0x97/0xb0 [amdgpu] [ 206.554353] edac_mce_amd(E) ee1004(E) [ 206.554270] amdgpu_irq_dispatch+0x150/0x230 [amdgpu] [ 206.554702] amdgpu_ih_process+0x6a/0x180 [amdgpu] [ 206.555101] amdgpu_irq_handler+0x23/0x60 [amdgpu] [ 206.555500] __handle_irq_event_percpu+0x4a/0x1c0 [ 206.555506] handle_irq_event+0x38/0x80 [ 206.555509] handle_edge_irq+0x92/0x1e0 [ 206.555513] __common_interrupt+0x3e/0xb0 [ 206.555519] common_interrupt+0x80/0xa0 [ 206.555525] </IRQ> [ 206.555527] <TASK> ... [ 206.555650] RIP: 0010:dma_fence_signal_timestamp_locked+0x39/0xe0 ... [ 206.555667] Kernel panic - not syncing: Fatal exception in interrupt

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: drm/amdkfd: Fix out-of-bounds write in kfd_event_page_set() (CVE-2026-43206)

• kernel: drm/amdgpu: Refactor amdgpu_gem_va_ioctl for Handling Last Fence Update and Timeline Management v4 (CVE-2026-43237)

• kernel: crypto: pcrypt - Fix handling of MAY_BACKLOG requests (CVE-2026-43493)

• kernel: udf: fix partition descriptor append bookkeeping (CVE-2026-45991)

• kernel: drm/amdkfd: Fix watch_id bounds checking in debug address watch v2 (CVE-2026-45878)

• kernel: smb/client: fix out-of-bounds read in symlink_data() (CVE-2026-46185)

• kernel: sched/psi: fix race between file release and pressure write (CVE-2026-52991)

• kernel: drm/amdkfd: Fix buffer overflow in SDMA queue checkpoint/restore on GFX11 (CVE-2026-53143)

• kernel: drm/amd/display: Clamp VBIOS HDMI retimer register count to array size (CVE-2026-53136)

• kernel: drm/amd/display: Use krealloc_array() in dal_vector_reserve() (CVE-2026-53329)

• kernel: drm/i915/gem: Fix phys BO pread/pwrite with offset (CVE-2026-53356)

• kernel: drm/amdgpu: zero-initialize GART table on allocation (CVE-2026-53374)

• kernel: drm/i915: Fix potential UAF in TTM object purge (CVE-2026-63884)

• kernel: scsi: target: iscsi: Validate CHAP_R length before base64 decode (CVE-2026-63886)

• kernel: memfd: deny writeable mappings when implying SEAL_WRITE (CVE-2026-63952)

• kernel: scsi: target: iscsi: Fix CRC overread and double-free in iscsit_handle_text_cmd() (CVE-2026-63888)

• kernel: blk-mq: pop cached request if it is usable (CVE-2026-64017)

• kernel: drm/amdgpu: fix amdgpu_hmm_range_get_pages (CVE-2026-63879)

• kernel: drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async (CVE-2026-64219)

• kernel: smb: client: fix double-free in SMB2_open() replay (CVE-2026-64382)

• kernel: smb: client: mask server-provided mode to 07777 in modefromsid (CVE-2026-64379)

• kernel: smb: client: fix query_info() replay double-free (CVE-2026-64386)

• kernel: posix-cpu-timers: Prevent UAF caused by non-leader exec() race (CVE-2026-64560)

• kernel: smb/client: handle overlapping allocated ranges in fallocate (CVE-2026-68388)

Bug Fix(es) and Enhancement(s):

• CLONE - Rocky Linux 10.2.z xfs: fix exchange-range reflink flag clearing issue with INO1_WRITTEN (JIRA:Rocky Linux-223954)

• vhost: reset the vring metadata cache on vring reconfiguration [rhel-10.2.z] (JIRA:Rocky Linux-224545)

• cifs: periodic IO errors when rename races with lease break [rhel-10.2.z] (JIRA:Rocky Linux-235459)

• cifs: smb1 directory listings from xp server returning EINVAL and EIO [rhel-10.2.z] (JIRA:Rocky Linux-235812)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: netfilter: nf_conntrack_h323: fix OOB read in decode_choice() (CVE-2026-43233)

• kernel: drm/amdkfd: Fix out-of-bounds write in kfd_event_page_set() (CVE-2026-43206)

• kernel: drm/amdgpu: Refactor amdgpu_gem_va_ioctl for Handling Last Fence Update and Timeline Management v4 (CVE-2026-43237)

• kernel: udf: fix partition descriptor append bookkeeping (CVE-2026-45991)

• kernel: drm/amdkfd: Fix watch_id bounds checking in debug address watch v2 (CVE-2026-45878)

• kernel: ip6_gre: Use cached t->net in ip6erspan_changelink() (CVE-2026-46120)

• kernel: sched/psi: fix race between file release and pressure write (CVE-2026-52991)

• kernel: drm/amdkfd: Fix buffer overflow in SDMA queue checkpoint/restore on GFX11 (CVE-2026-53143)

• kernel: drm/amd/display: Clamp VBIOS HDMI retimer register count to array size (CVE-2026-53136)

• kernel: mm/huge_memory: update file PMD counter before folio_put() (CVE-2026-53189)

• kernel: drm/amd/display: Use krealloc_array() in dal_vector_reserve() (CVE-2026-53329)

• kernel: drm/i915/gem: Fix phys BO pread/pwrite with offset (CVE-2026-53356)

• kernel: drm/amdgpu: zero-initialize GART table on allocation (CVE-2026-53374)

• kernel: drm/i915: Fix potential UAF in TTM object purge (CVE-2026-63884)

• kernel: netfilter: synproxy: refresh tcphdr after skb_ensure_writable (CVE-2026-64007)

• kernel: memfd: deny writeable mappings when implying SEAL_WRITE (CVE-2026-63952)

• kernel: scsi: target: iscsi: Fix CRC overread and double-free in iscsit_handle_text_cmd() (CVE-2026-63888)

• kernel: drm/amdgpu: fix amdgpu_hmm_range_get_pages (CVE-2026-63879)

• kernel: net/smc: reject CHID-0 ACCEPT that matches an empty ism_dev slot (CVE-2026-64048)

• kernel: drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async (CVE-2026-64219)

• kernel: smb: client: fix double-free in SMB2_open() replay (CVE-2026-64382)

• kernel: smb: client: mask server-provided mode to 07777 in modefromsid (CVE-2026-64379)

• kernel: smb: client: fix query_info() replay double-free (CVE-2026-64386)

• kernel: posix-cpu-timers: Prevent UAF caused by non-leader exec() race (CVE-2026-64560)

• kernel: smb: client: validate DFS referral PathConsumed (CVE-2026-68343)

• kernel: smb/client: handle overlapping allocated ranges in fallocate (CVE-2026-68388)

Bug Fix(es) and Enhancement(s):

• kernel 5.14.0-687.5.1.el9_8 breaks wifi when using FIPS (JIRA:Rocky Linux-181065)

• vhost: reset the vring metadata cache on vring reconfiguration [rhel-9.8.z] (JIRA:Rocky Linux-224549)

• cifs: smb1 directory listings from xp server returning EINVAL and EIO [rhel-9.8.z] (JIRA:Rocky Linux-235811)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Refactor amdgpu_gem_va_ioctl for Handling Last Fence Update and Timeline Management v4 This commit simplifies the amdgpu_gem_va_ioctl function, key updates include: - Moved the logic for managing the last update fence directly into amdgpu_gem_va_update_vm. - Introduced checks for the timeline point to enable conditional replacement or addition of fences. v2: Addressed review comments from Christian. v3: Updated comments (Christian). v4: The previous version selected the fence too early and did not manage its reference correctly, which could lead to stale or freed fences being used. This resulted in refcount underflows and could crash when updating GPU timelines. The fence is now chosen only after the VA mapping work is completed, and its reference is taken safely. After exporting it to the VM timeline syncobj, the driver always drops its local fence reference, ensuring balanced refcounting and avoiding use-after-free on dma_fence. Crash signature: [ 205.828135] refcount_t: underflow; use-after-free. [ 205.832963] WARNING: CPU: 30 PID: 7274 at lib/refcount.c:28 refcount_warn_saturate+0xbe/0x110 ... [ 206.074014] Call Trace: [ 206.076488] <TASK> [ 206.078608] amdgpu_gem_va_ioctl+0x6ea/0x740 [amdgpu] [ 206.084040] ? __pfx_amdgpu_gem_va_ioctl+0x10/0x10 [amdgpu] [ 206.089994] drm_ioctl_kernel+0x86/0xe0 [drm] [ 206.094415] drm_ioctl+0x26e/0x520 [drm] [ 206.098424] ? __pfx_amdgpu_gem_va_ioctl+0x10/0x10 [amdgpu] [ 206.104402] amdgpu_drm_ioctl+0x4b/0x80 [amdgpu] [ 206.109387] __x64_sys_ioctl+0x96/0xe0 [ 206.113156] do_syscall_64+0x66/0x2d0 ... [ 206.553351] BUG: unable to handle page fault for address: ffffffffc0dfde90 ... [ 206.553378] RIP: 0010:dma_fence_signal_timestamp_locked+0x39/0xe0 ... [ 206.553405] Call Trace: [ 206.553409] <IRQ> [ 206.553415] ? __pfx_drm_sched_fence_free_rcu+0x10/0x10 [gpu_sched] [ 206.553424] dma_fence_signal+0x30/0x60 [ 206.553427] drm_sched_job_done.isra.0+0x123/0x150 [gpu_sched] [ 206.553434] dma_fence_signal_timestamp_locked+0x6e/0xe0 [ 206.553437] dma_fence_signal+0x30/0x60 [ 206.553441] amdgpu_fence_process+0xd8/0x150 [amdgpu] [ 206.553854] sdma_v4_0_process_trap_irq+0x97/0xb0 [amdgpu] [ 206.554353] edac_mce_amd(E) ee1004(E) [ 206.554270] amdgpu_irq_dispatch+0x150/0x230 [amdgpu] [ 206.554702] amdgpu_ih_process+0x6a/0x180 [amdgpu] [ 206.555101] amdgpu_irq_handler+0x23/0x60 [amdgpu] [ 206.555500] __handle_irq_event_percpu+0x4a/0x1c0 [ 206.555506] handle_irq_event+0x38/0x80 [ 206.555509] handle_edge_irq+0x92/0x1e0 [ 206.555513] __common_interrupt+0x3e/0xb0 [ 206.555519] common_interrupt+0x80/0xa0 [ 206.555525] </IRQ> [ 206.555527] <TASK> ... [ 206.555650] RIP: 0010:dma_fence_signal_timestamp_locked+0x39/0xe0 ... [ 206.555667] Kernel panic - not syncing: Fatal exception in interrupt

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: drm/amdkfd: Fix out-of-bounds write in kfd_event_page_set() (CVE-2026-43206)
• kernel: drm/amdgpu: Refactor amdgpu_gem_va_ioctl for Handling Last Fence Update and Timeline Management v4 (CVE-2026-43237)
• kernel: crypto: pcrypt - Fix handling of MAY_BACKLOG requests (CVE-2026-43493)
• kernel: udf: fix partition descriptor append bookkeeping (CVE-2026-45991)
• kernel: drm/amdkfd: Fix watch_id bounds checking in debug address watch v2 (CVE-2026-45878)
• kernel: smb/client: fix out-of-bounds read in symlink_data() (CVE-2026-46185)
• kernel: sched/psi: fix race between file release and pressure write (CVE-2026-52991)
• kernel: drm/amdkfd: Fix buffer overflow in SDMA queue checkpoint/restore on GFX11 (CVE-2026-53143)
• kernel: drm/amd/display: Clamp VBIOS HDMI retimer register count to array size (CVE-2026-53136)
• kernel: drm/amd/display: Use krealloc_array() in dal_vector_reserve() (CVE-2026-53329)
• kernel: drm/i915/gem: Fix phys BO pread/pwrite with offset (CVE-2026-53356)
• kernel: drm/amdgpu: zero-initialize GART table on allocation (CVE-2026-53374)
• kernel: drm/i915: Fix potential UAF in TTM object purge (CVE-2026-63884)
• kernel: scsi: target: iscsi: Validate CHAP_R length before base64 decode (CVE-2026-63886)
• kernel: memfd: deny writeable mappings when implying SEAL_WRITE (CVE-2026-63952)
• kernel: scsi: target: iscsi: Fix CRC overread and double-free in iscsit_handle_text_cmd() (CVE-2026-63888)
• kernel: blk-mq: pop cached request if it is usable (CVE-2026-64017)
• kernel: drm/amdgpu: fix amdgpu_hmm_range_get_pages (CVE-2026-63879)
• kernel: drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async (CVE-2026-64219)
• kernel: smb: client: fix double-free in SMB2_open() replay (CVE-2026-64382)
• kernel: smb: client: mask server-provided mode to 07777 in modefromsid (CVE-2026-64379)
• kernel: smb: client: fix query_info() replay double-free (CVE-2026-64386)
• kernel: posix-cpu-timers: Prevent UAF caused by non-leader exec() race (CVE-2026-64560)
• kernel: smb/client: handle overlapping allocated ranges in fallocate (CVE-2026-68388)

Bug Fix(es) and Enhancement(s):

• CLONE - AlmaLinux 10.2.z xfs: fix exchange-range reflink flag clearing issue with INO1_WRITTEN (JIRA:AlmaLinux-223954)
• vhost: reset the vring metadata cache on vring reconfiguration [almalinux-10.2.z] (JIRA:AlmaLinux-224545)
• cifs: periodic IO errors when rename races with lease break [almalinux-10.2.z] (JIRA:AlmaLinux-235459)
• cifs: smb1 directory listings from xp server returning EINVAL and EIO [almalinux-10.2.z] (JIRA:AlmaLinux-235812)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: netfilter: nf_conntrack_h323: fix OOB read in decode_choice() (CVE-2026-43233)
• kernel: drm/amdkfd: Fix out-of-bounds write in kfd_event_page_set() (CVE-2026-43206)
• kernel: drm/amdgpu: Refactor amdgpu_gem_va_ioctl for Handling Last Fence Update and Timeline Management v4 (CVE-2026-43237)
• kernel: udf: fix partition descriptor append bookkeeping (CVE-2026-45991)
• kernel: drm/amdkfd: Fix watch_id bounds checking in debug address watch v2 (CVE-2026-45878)
• kernel: ip6_gre: Use cached t->net in ip6erspan_changelink() (CVE-2026-46120)
• kernel: sched/psi: fix race between file release and pressure write (CVE-2026-52991)
• kernel: drm/amdkfd: Fix buffer overflow in SDMA queue checkpoint/restore on GFX11 (CVE-2026-53143)
• kernel: drm/amd/display: Clamp VBIOS HDMI retimer register count to array size (CVE-2026-53136)
• kernel: mm/huge_memory: update file PMD counter before folio_put() (CVE-2026-53189)
• kernel: drm/amd/display: Use krealloc_array() in dal_vector_reserve() (CVE-2026-53329)
• kernel: drm/i915/gem: Fix phys BO pread/pwrite with offset (CVE-2026-53356)
• kernel: drm/amdgpu: zero-initialize GART table on allocation (CVE-2026-53374)
• kernel: drm/i915: Fix potential UAF in TTM object purge (CVE-2026-63884)
• kernel: netfilter: synproxy: refresh tcphdr after skb_ensure_writable (CVE-2026-64007)
• kernel: memfd: deny writeable mappings when implying SEAL_WRITE (CVE-2026-63952)
• kernel: scsi: target: iscsi: Fix CRC overread and double-free in iscsit_handle_text_cmd() (CVE-2026-63888)
• kernel: drm/amdgpu: fix amdgpu_hmm_range_get_pages (CVE-2026-63879)
• kernel: net/smc: reject CHID-0 ACCEPT that matches an empty ism_dev slot (CVE-2026-64048)
• kernel: drm/amd/display: Validate payload length and link_index in dc_process_dmub_aux_transfer_async (CVE-2026-64219)
• kernel: smb: client: fix double-free in SMB2_open() replay (CVE-2026-64382)
• kernel: smb: client: mask server-provided mode to 07777 in modefromsid (CVE-2026-64379)
• kernel: smb: client: fix query_info() replay double-free (CVE-2026-64386)
• kernel: posix-cpu-timers: Prevent UAF caused by non-leader exec() race (CVE-2026-64560)
• kernel: smb: client: validate DFS referral PathConsumed (CVE-2026-68343)
• kernel: smb/client: handle overlapping allocated ranges in fallocate (CVE-2026-68388)

Bug Fix(es) and Enhancement(s):

• kernel 5.14.0-687.5.1.el9_8 breaks wifi when using FIPS (JIRA:AlmaLinux-181065)
• vhost: reset the vring metadata cache on vring reconfiguration [almalinux-9.8.z] (JIRA:AlmaLinux-224549)
• cifs: smb1 directory listings from xp server returning EINVAL and EIO [almalinux-9.8.z] (JIRA:AlmaLinux-235811)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

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

drm/amdgpu: Refactor amdgpu_gem_va_ioctl for Handling Last Fence Update and Timeline Management v4

This commit simplifies the amdgpu_gem_va_ioctl function, key updates include:

• Moved the logic for managing the last update fence directly into amdgpu_gem_va_update_vm.
• Introduced checks for the timeline point to enable conditional replacement or addition of fences.

v2: Addressed review comments from Christian. v3: Updated comments (Christian). v4: The previous version selected the fence too early and did not manage its reference correctly, which could lead to stale or freed fences being used. This resulted in refcount underflows and could crash when updating GPU timelines. The fence is now chosen only after the VA mapping work is completed, and its reference is taken safely. After exporting it to the VM timeline syncobj, the driver always drops its local fence reference, ensuring balanced refcounting and avoiding use-after-free on dma_fence.

Crash signature:
[  205.828135] refcount_t: underflow; use-after-free.
[  205.832963] WARNING: CPU: 30 PID: 7274 at lib/refcount.c:28 refcount_warn_saturate+0xbe/0x110
...
[  206.074014] Call Trace:
[  206.076488]  <TASK>
[  206.078608]  amdgpu_gem_va_ioctl+0x6ea/0x740 [amdgpu]
[  206.084040]  ? __pfx_amdgpu_gem_va_ioctl+0x10/0x10 [amdgpu]
[  206.089994]  drm_ioctl_kernel+0x86/0xe0 [drm]
[  206.094415]  drm_ioctl+0x26e/0x520 [drm]
[  206.098424]  ? __pfx_amdgpu_gem_va_ioctl+0x10/0x10 [amdgpu]
[  206.104402]  amdgpu_drm_ioctl+0x4b/0x80 [amdgpu]
[  206.109387]  __x64_sys_ioctl+0x96/0xe0
[  206.113156]  do_syscall_64+0x66/0x2d0
...
[  206.553351] BUG: unable to handle page fault for address: ffffffffc0dfde90
...
[  206.553378] RIP: 0010:dma_fence_signal_timestamp_locked+0x39/0xe0
...
[  206.553405] Call Trace:
[  206.553409]  <IRQ>
[  206.553415]  ? __pfx_drm_sched_fence_free_rcu+0x10/0x10 [gpu_sched]
[  206.553424]  dma_fence_signal+0x30/0x60
[  206.553427]  drm_sched_job_done.isra.0+0x123/0x150 [gpu_sched]
[  206.553434]  dma_fence_signal_timestamp_locked+0x6e/0xe0
[  206.553437]  dma_fence_signal+0x30/0x60
[  206.553441]  amdgpu_fence_process+0xd8/0x150 [amdgpu]
[  206.553854]  sdma_v4_0_process_trap_irq+0x97/0xb0 [amdgpu]
[  206.554353]  edac_mce_amd(E) ee1004(E)
[  206.554270]  amdgpu_irq_dispatch+0x150/0x230 [amdgpu]
[  206.554702]  amdgpu_ih_process+0x6a/0x180 [amdgpu]
[  206.555101]  amdgpu_irq_handler+0x23/0x60 [amdgpu]
[  206.555500]  __handle_irq_event_percpu+0x4a/0x1c0
[  206.555506]  handle_irq_event+0x38/0x80
[  206.555509]  handle_edge_irq+0x92/0x1e0
[  206.555513]  __common_interrupt+0x3e/0xb0
[  206.555519]  common_interrupt+0x80/0xa0
[  206.555525]  </IRQ>
[  206.555527]  <TASK>
...
[  206.555650] RIP: 0010:dma_fence_signal_timestamp_locked+0x39/0xe0
...
[  206.555667] Kernel panic - not syncing: Fatal exception in interrupt

Root has patched CVE-2026-43237 in the linux package for Root:Debian:11. Multiple fixed versions available.

Root has patched CVE-2026-43237 in the linux package for Root:Debian:12. Multiple fixed versions available.

Root has patched CVE-2026-43237 in the linux package for Root:Ubuntu:22.04. Multiple fixed versions available.

Root has patched CVE-2026-43237 in the linux package for Root:Ubuntu:24.04. Multiple fixed versions available.