CVE-2022-49834

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix use-after-free bug of ns_writer on remount If a nilfs2 filesystem is downgraded to read-only due to metadata corruption on disk and is remounted read/write, or if emergency read-only remount is performed, detaching a log writer and synchronizing the filesystem can be done at the same time. In these cases, use-after-free of the log writer (hereinafter nilfs->ns_writer) can happen as shown in the scenario below: Task1 Task2 -------------------------------- ------------------------------ nilfs_construct_segment nilfs_segctor_sync init_wait init_waitqueue_entry add_wait_queue schedule nilfs_remount (R/W remount case) nilfs_attach_log_writer nilfs_detach_log_writer nilfs_segctor_destroy kfree finish_wait _raw_spin_lock_irqsave __raw_spin_lock_irqsave do_raw_spin_lock debug_spin_lock_before <-- use-after-free While Task1 is sleeping, nilfs->ns_writer is freed by Task2. After Task1 waked up, Task1 accesses nilfs->ns_writer which is already freed. This scenario diagram is based on the Shigeru Yoshida's post [1]. This patch fixes the issue by not detaching nilfs->ns_writer on remount so that this UAF race doesn't happen. Along with this change, this patch also inserts a few necessary read-only checks with superblock instance where only the ns_writer pointer was used to check if the filesystem is read-only.

• CVE-2022-49416
  • wifi: mac80211: fix use-after-free in chanctx code {CVE-2022-49416}
• CVE-2022-49685
  • iio: trigger: sysfs: fix use-after-free on remove {CVE-2022-49685}
• CVE-2021-47670
  • can: peak_usb: fix use after free bugs {CVE-2021-47670}
• CVE-2026-98706
  • wifi: mac80211: drain PS delivery work during station teardown {CVE-2026-98706}
• CVE-2026-98610
  • net/sched: sch_hfsc: bound the classify inner-filter walk with a drift budget {CVE-2026-98610}
• CVE-2026-98548
  • sctp: discard the rest of the packet on a stale-cookie error {CVE-2026-98548}
• CVE-2026-98614
  • sctp: avoid livelock while updating retransmit path {CVE-2026-98614}
• CVE-2026-98547
  • af_packet: fix integer overflow in prb_calc_retire_blk_tmo() {CVE-2026-98547}
• CVE-2026-98579
  • nfc: llcp: fix sdreq TLV list leak on parse/alloc/send failure {CVE-2026-98579}
• CVE-2026-98581
  • nfc: llcp: Fix list corruption / refcount desync in nfc_llcp_recv_dm() {CVE-2026-98581}
• CVE-2026-98577
  • nfc: llcp: fix WKS SAP hijacking via prefix match in nfc_llcp_wks_sap() {CVE-2026-98577}
• CVE-2026-98482
  • nfc: llcp: drop truncated I/RR/RNR PDUs in nfc_llcp_recv_hdlc() {CVE-2026-98482}
• CVE-2026-98576
  • nfc: llcp: fix slab-out-of-bounds reads when logging service names {CVE-2026-98576}
• CVE-2026-98624
  • netfilter: nfnetlink_queue: hold nfnl mutex in event notifier {CVE-2026-98624}
  • netlink: use blocking notifier {CVE-2026-98624}
• CVE-2026-98794
  • ipvs: filter some flags received in the backup server {CVE-2026-98794}
• CVE-2026-98829
  • wifi: mac80211: drop oversized fragments to avoid extra_len overflow {CVE-2026-98829}
• CVE-2026-98708
  • wifi: mac80211: keep paired old chanctx alive {CVE-2026-98708}
• CVE-2026-98707
  • wifi: mac80211: shut down RX BA session timer on teardown {CVE-2026-98707}
• CVE-2026-98532
  • ipv6: do not let ipv6_find_hdr() return an offset past the packet end {CVE-2026-98532}
• CVE-2026-98541
  • fou: reject omitted FOU_ATTR_IPPROTO on FOU_ENCAP_DIRECT {CVE-2026-98541}
• CVE-2026-98461
  • Bluetooth: hci_sock: validate event length before filtering {CVE-2026-98461}
• CVE-2026-98621
  • net: gue: reject invalid REMCSUM offsets {CVE-2026-98621}
• CVE-2026-98526
  • llc: reserve device headroom for allocated frames {CVE-2026-98526}
• CVE-2026-98555
  • llc: fix skb UAF and leaks on llc_mac_hdr_init() failure {CVE-2026-98555}
• CVE-2026-98573
  • net: skbuff: fix pull-bound underflow in skb_checksum_setup_ipv6() {CVE-2026-98573}
• CVE-2026-98739
  • Bluetooth: RFCOMM: Fix initial port reference race {CVE-2026-98739}
• CVE-2026-98457
  • Bluetooth: L2CAP: validate frame length before control and FCS access {CVE-2026-98457}
• CVE-2026-98460
  • Bluetooth: hci_sock: reject out-of-range OCF values {CVE-2026-98460}
• CVE-2026-98856
  • kprobes: Skip disarmed probes when checking optkprobe overlap {CVE-2026-98856}
• CVE-2026-98636
  • squashfs: Add dictionary size range check to prevent shift-out-of-bounds {CVE-2026-98636}
• CVE-2026-98681
  • smb: client: split cifsFileInfo bitfields to avoid shared-byte RMW races {CVE-2026-98681}
• CVE-2026-98771
  • usb: storage: sierra_ms: reject short SWoC info transfers {CVE-2026-98771}
• CVE-2026-98772
  • USB: serial: fix port tear down use-after-free {CVE-2026-98772}
• CVE-2026-98696
  • USB: serial: fix driver deregistration order {CVE-2026-98696}
• CVE-2026-98697
  • USB: serial: fix dynamic id driver deregistration race {CVE-2026-98697}
• CVE-2026-98769
  • usb: gadget: f_uac1_legacy: validate bRequest index in generic_{set,get}_cmd {CVE-2026-98769}
• CVE-2026-98764
  • usb: gadget: f_fs: Fix NULL pointer dereference in …

The SUSE Linux Enterprise 15 SP4 RT kernel was updated to receive various security bugfixes.

The following security bugs were fixed:

• CVE-2022-49110: netfilter: conntrack: revisit gc autotuning (bsc#1237981).
• CVE-2022-49139: Bluetooth: fix null ptr deref on hci_sync_conn_complete_evt (bsc#1238032).
• CVE-2022-49767: 9p/trans_fd: always use O_NONBLOCK read/write (bsc#1242493).
• CVE-2022-49775: tcp: cdg: allow tcp_cdg_release() to be called multiple times (bsc#1242245).
• CVE-2024-53168: net: make sock_inuse_add() available (bsc#1234887).
• CVE-2024-56558: nfsd: make sure exp active before svc_export_show (bsc#1235100).
• CVE-2025-21888: RDMA/mlx5: Fix a WARN during dereg_mr for DM type (bsc#1240177).
• CVE-2025-21999: proc: fix UAF in proc_get_inode() (bsc#1240802).
• CVE-2025-22056: netfilter: nft_tunnel: fix geneve_opt type confusion addition (bsc#1241525).
• CVE-2025-22060: net: mvpp2: Prevent parser TCAM memory corruption (bsc#1241526).
• CVE-2025-23138: watch_queue: fix pipe accounting mismatch (bsc#1241648).
• CVE-2025-23145: mptcp: fix NULL pointer in can_accept_new_subflow (bsc#1242596).
• CVE-2025-37785: ext4: fix OOB read when checking dotdot dir (bsc#1241640).
• CVE-2025-37789: net: openvswitch: fix nested key length validation in the set() action (bsc#1242762).

The following non-security bugs were fixed:

• Drivers: hv: Allow vmbus_sendpacket_mpb_desc() to create multiple ranges (bsc#1243737).
• Refresh fixes for cBPF issue (bsc#1242778)
• Remove debug flavor (bsc#1243919)
• arm64: bpf: Add BHB mitigation to the epilogue for cBPF programs (bsc#1242778).
• arm64: bpf: Only mitigate cBPF programs loaded by unprivileged users (bsc#1242778).
• arm64: insn: Add support for encoding DSB (bsc#1242778).
• arm64: proton-pack: Add new CPUs 'k' values for branch mitigation (bsc#1242778).
• arm64: proton-pack: Expose whether the branchy loop k value (bsc#1242778).
• arm64: proton-pack: Expose whether the platform is mitigated by firmware (bsc#1242778).
• hv_netvsc: Preserve contiguous PFN grouping in the page buffer array (bsc#1243737).
• hv_netvsc: Remove rmsg_pgcnt (bsc#1243737).
• hv_netvsc: Use vmbus_sendpacket_mpb_desc() to send VMBus messages (bsc#1243737).
• mtd: phram: Add the kernel lock down check (bsc#1232649).
• ocfs2: fix the issue with discontiguous allocation in the global_bitmap (git-fixes).
• powerpc/pseries/iommu: IOMMU incorrectly marks MMIO range in DDW (bsc#1218470 ltc#204531).
• scsi: core: Fix unremoved procfs host directory regression (git-fixes).
• scsi: storvsc: Set correct data length for sending SCSI command without payload (git-fixes).
• x86/bhi: Do not set BHI_DIS_S in 32-bit mode (bsc#1242778).
• x86/bpf: Add IBHF call at end of classic BPF (bsc#1242778).
• x86/bpf: Call branch history clearing sequence on exit (bsc#1242778).

The SUSE Linux Enterprise 15 SP5 RT kernel was updated to receive various security bugfixes.

The following security bugs were fixed:

• CVE-2022-49775: tcp: cdg: allow tcp_cdg_release() to be called multiple times (bsc#1242245).
• CVE-2024-53168: net: make sock_inuse_add() available (bsc#1234887).
• CVE-2024-56558: nfsd: make sure exp active before svc_export_show (bsc#1235100).
• CVE-2025-21999: proc: fix UAF in proc_get_inode() (bsc#1240802).
• CVE-2025-22056: netfilter: nft_tunnel: fix geneve_opt type confusion addition (bsc#1241525).
• CVE-2025-23145: mptcp: fix NULL pointer in can_accept_new_subflow (bsc#1242596).
• CVE-2025-37789: net: openvswitch: fix nested key length validation in the set() action (bsc#1242762).

The following non-security bugs were fixed:

• Drivers: hv: Allow vmbus_sendpacket_mpb_desc() to create multiple ranges (bsc#1243737).
• Remove debug flavor (bsc#1243919).
• arm64: bpf: Add BHB mitigation to the epilogue for cBPF programs (bsc#1242778).
• arm64: bpf: Only mitigate cBPF programs loaded by unprivileged users (bsc#1242778).
• arm64: insn: Add support for encoding DSB (bsc#1242778).
• arm64: proton-pack: Add new CPUs 'k' values for branch mitigation (bsc#1242778).
• arm64: proton-pack: Expose whether the branchy loop k value (bsc#1242778).
• arm64: proton-pack: Expose whether the platform is mitigated by firmware (bsc#1242778).
• hv_netvsc: Preserve contiguous PFN grouping in the page buffer array (bsc#1243737).
• hv_netvsc: Remove rmsg_pgcnt (bsc#1243737).
• hv_netvsc: Use vmbus_sendpacket_mpb_desc() to send VMBus messages (bsc#1243737).
• mtd: phram: Add the kernel lock down check (bsc#1232649).
• net :mana :Add remaining GDMA stats for MANA to ethtool (bsc#1234395).
• net :mana :Request a V2 response version for MANA_QUERY_GF_STAT (bsc#1234395).
• net: mana: Add gdma stats to ethtool output for mana (bsc#1234395).
• nvme-pci: acquire cq_poll_lock in nvme_poll_irqdisable (bsc#1223096).
• ocfs2: fix the issue with discontiguous allocation in the global_bitmap (git-fixes).
• powerpc/pseries/iommu: IOMMU incorrectly marks MMIO range in DDW (bsc#1218470 ltc#204531).
• scsi: core: Fix unremoved procfs host directory regression (git-fixes).
• tcp: Dump bound-only sockets in inet_diag (bsc#1204562).
• tpm, tpm_tis: Workaround failed command reception on Infineon devices (bsc#1235870).
• tpm: tis: Double the timeout B to 4s (bsc#1235870).
• x86/bhi: Do not set BHI_DIS_S in 32-bit mode (bsc#1242778).
• x86/bpf: Add IBHF call at end of classic BPF (bsc#1242778).
• x86/bpf: Call branch history clearing sequence on exit (bsc#1242778).

The SUSE Linux Enterprise 15 SP5 kernel was updated to receive various security bugfixes.

The following security bugs were fixed:

• CVE-2022-49775: tcp: cdg: allow tcp_cdg_release() to be called multiple times (bsc#1242245).
• CVE-2024-53168: net: make sock_inuse_add() available (bsc#1234887).
• CVE-2024-56558: nfsd: make sure exp active before svc_export_show (bsc#1235100).
• CVE-2025-21999: proc: fix UAF in proc_get_inode() (bsc#1240802).
• CVE-2025-22056: netfilter: nft_tunnel: fix geneve_opt type confusion addition (bsc#1241525).
• CVE-2025-23145: mptcp: fix NULL pointer in can_accept_new_subflow (bsc#1242596).
• CVE-2025-37789: net: openvswitch: fix nested key length validation in the set() action (bsc#1242762).
• CVE-2024-28956: x86/its: Add support for ITS-safe indirect thunk (bsc#1242006).
• CVE-2025-37785: ext4: fix OOB read when checking dotdot dir (bsc#1241640).

The following non-security bugs were fixed:

• Drivers: hv: Allow vmbus_sendpacket_mpb_desc() to create multiple ranges (bsc#1243737).
• Move upstreamed sched/membarrier patch into sorted section
• Remove debug flavor (bsc#1243919). This is only released in Leap, and we do not have Leap 15.4 anymore.
• Remove debug flavor (bsc#1243919). This is only released in Leap, and we do not have Leap 15.5 anymore.
• Use gcc-13 for build on SLE16 (jsc#PED-10028).
• arm64: bpf: Add BHB mitigation to the epilogue for cBPF programs (bsc#1242778).
• arm64: bpf: Only mitigate cBPF programs loaded by unprivileged users (bsc#1242778).
• arm64: insn: Add support for encoding DSB (bsc#1242778).
• arm64: proton-pack: Add new CPUs 'k' values for branch mitigation (bsc#1242778).
• arm64: proton-pack: Expose whether the branchy loop k value (bsc#1242778).
• arm64: proton-pack: Expose whether the platform is mitigated by firmware (bsc#1242778).
• hv_netvsc: Preserve contiguous PFN grouping in the page buffer array (bsc#1243737).
• hv_netvsc: Remove rmsg_pgcnt (bsc#1243737).
• hv_netvsc: Use vmbus_sendpacket_mpb_desc() to send VMBus messages (bsc#1243737).
• mtd: phram: Add the kernel lock down check (bsc#1232649).
• net :mana :Add remaining GDMA stats for MANA to ethtool (bsc#1234395).
• net :mana :Request a V2 response version for MANA_QUERY_GF_STAT (bsc#1234395).
• net: mana: Add gdma stats to ethtool output for mana (bsc#1234395).
• nvme-pci: acquire cq_poll_lock in nvme_poll_irqdisable (bsc#1223096).
• ocfs2: fix the issue with discontiguous allocation in the global_bitmap (git-fixes).
• powerpc/pseries/iommu: IOMMU incorrectly marks MMIO range in DDW (bsc#1218470 ltc#204531).
• rpm/kernel-binary.spec.in: Also order against update-bootloader (boo#1228659, boo#1240785, boo#1241038).
• rpm/kernel-binary.spec.in: Fix missing 20-kernel-default-extra.conf (bsc#1239986)
• rpm/kernel-binary.spec.in: fix KMPs build on 6.13+ (bsc#1234454)
• rpm/kernel-docs.spec.in: Workaround for reproducible builds (bsc#1238303)
• rpm/release-projects: Update the ALP projects again (bsc#1231293).
• rpm/split-modules: Fix optional splitting with usrmerge (bsc#1238570)
• scsi: core: Fix unremoved procfs host directory regression (git-fixes).
• tcp: Dump bound-only sockets in inet_diag (bsc#1204562).
• tpm, tpm_tis: Workaround failed command reception on Infineon devices (bsc#1235870).
• tpm: tis: Double the timeout B to 4s (bsc#1235870).
• x86/bhi: Do not set BHI_DIS_S in 32-bit mode (bsc#1242778).
• x86/bpf: Add IBHF call at end of classic BPF (bsc#1242778).
• x86/bpf: Call branch history clearing sequence on exit (bsc#1242778).

The SUSE Linux Enterprise 15 SP4 kernel was updated to receive various security bugfixes.

The following security bugs were fixed:

• CVE-2022-49110: netfilter: conntrack: revisit gc autotuning (bsc#1237981).
• CVE-2022-49139: Bluetooth: fix null ptr deref on hci_sync_conn_complete_evt (bsc#1238032).
• CVE-2022-49767: 9p/trans_fd: always use O_NONBLOCK read/write (bsc#1242493).
• CVE-2022-49775: tcp: cdg: allow tcp_cdg_release() to be called multiple times (bsc#1242245).
• CVE-2022-49858: octeontx2-pf: Fix SQE threshold checking (bsc#1242589).
• CVE-2023-53058: net/mlx5: E-Switch, Fix an Oops in error handling code (bsc#1242237).
• CVE-2023-53060: igb: revert rtnl_lock() that causes deadlock (bsc#1242241).
• CVE-2023-53064: iavf: Fix hang on reboot with ice (bsc#1242222).
• CVE-2023-53066: qed/qed_sriov: guard against NULL derefs from qed_iov_get_vf_info (bsc#1242227).
• CVE-2023-53079: net/mlx5: Fix steering rules cleanup (bsc#1242765).
• CVE-2023-53114: i40e: Fix kernel crash during reboot when adapter is in recovery mode (bsc#1242398).
• CVE-2023-53134: bnxt_en: Avoid order-5 memory allocation for TPA data (bsc#1242380)
• CVE-2024-53168: net: make sock_inuse_add() available (bsc#1234887).
• CVE-2024-56558: nfsd: make sure exp active before svc_export_show (bsc#1235100).
• CVE-2025-21888: RDMA/mlx5: Fix a WARN during dereg_mr for DM type (bsc#1240177).
• CVE-2025-21999: proc: fix UAF in proc_get_inode() (bsc#1240802).
• CVE-2025-22056: netfilter: nft_tunnel: fix geneve_opt type confusion addition (bsc#1241525).
• CVE-2025-22060: net: mvpp2: Prevent parser TCAM memory corruption (bsc#1241526).
• CVE-2025-23138: watch_queue: fix pipe accounting mismatch (bsc#1241648).
• CVE-2025-23145: mptcp: fix NULL pointer in can_accept_new_subflow (bsc#1242596).
• CVE-2025-37785: ext4: fix OOB read when checking dotdot dir (bsc#1241640).
• CVE-2025-37789: net: openvswitch: fix nested key length validation in the set() action (bsc#1242762).

The following non-security bugs were fixed:

• Refresh fixes for cBPF issue (bsc#1242778)
• Remove debug flavor (bsc#1243919).
• Update metadata and put them into the sorted part of the series
• arm64: bpf: Add BHB mitigation to the epilogue for cBPF programs (bsc#1242778).
• arm64: bpf: Only mitigate cBPF programs loaded by unprivileged users (bsc#1242778).
• arm64: insn: Add support for encoding DSB (bsc#1242778).
• arm64: proton-pack: Add new CPUs 'k' values for branch mitigation (bsc#1242778).
• arm64: proton-pack: Expose whether the branchy loop k value (bsc#1242778).
• arm64: proton-pack: Expose whether the platform is mitigated by firmware (bsc#1242778).
• hv: Allow vmbus_sendpacket_mpb_desc() to create multiple ranges (bsc#1243737).
• hv_netvsc: Preserve contiguous PFN grouping in the page buffer array (bsc#1243737).
• hv_netvsc: Remove rmsg_pgcnt (bsc#1243737).
• hv_netvsc: Use vmbus_sendpacket_mpb_desc() to send VMBus messages (bsc#1243737).
• mtd: phram: Add the kernel lock down check (bsc#1232649).
• ocfs2: fix the issue with discontiguous allocation in the global_bitmap (git-fixes).
• powerpc/pseries/iommu: IOMMU incorrectly marks MMIO range in DDW (bsc#1218470 ltc#204531).
• scsi: core: Fix unremoved procfs host directory regression (git-fixes).
• scsi: storvsc: Set correct data length for sending SCSI command without payload (git-fixes).
• x86/bhi: Do not set BHI_DIS_S in 32-bit mode (bsc#1242778).
• x86/bpf: Add IBHF call at end of classic BPF (bsc#1242778).
• x86/bpf: Call branch history clearing sequence on exit (bsc#1242778).

The SUSE Linux Enterprise 15 SP5 kernel was updated to receive various security bugfixes.

The following security bugs were fixed:

• CVE-2022-49775: tcp: cdg: allow tcp_cdg_release() to be called multiple times (bsc#1242245).
• CVE-2024-53168: net: make sock_inuse_add() available (bsc#1234887).
• CVE-2024-56558: nfsd: make sure exp active before svc_export_show (bsc#1235100).
• CVE-2025-21999: proc: fix UAF in proc_get_inode() (bsc#1240802).
• CVE-2025-22056: netfilter: nft_tunnel: fix geneve_opt type confusion addition (bsc#1241525).
• CVE-2025-23145: mptcp: fix NULL pointer in can_accept_new_subflow (bsc#1242596).
• CVE-2025-37789: net: openvswitch: fix nested key length validation in the set() action (bsc#1242762).
• CVE-2024-28956: x86/its: Add support for ITS-safe indirect thunk (bsc#1242006).
• CVE-2025-37785: ext4: fix OOB read when checking dotdot dir (bsc#1241640).

The following non-security bugs were fixed:

• Drivers: hv: Allow vmbus_sendpacket_mpb_desc() to create multiple ranges (bsc#1243737).
• Move upstreamed sched/membarrier patch into sorted section
• Remove debug flavor (bsc#1243919). This is only released in Leap, and we do not have Leap 15.4 anymore.
• Remove debug flavor (bsc#1243919). This is only released in Leap, and we do not have Leap 15.5 anymore.
• Use gcc-13 for build on SLE16 (jsc#PED-10028).
• arm64: bpf: Add BHB mitigation to the epilogue for cBPF programs (bsc#1242778).
• arm64: bpf: Only mitigate cBPF programs loaded by unprivileged users (bsc#1242778).
• arm64: insn: Add support for encoding DSB (bsc#1242778).
• arm64: proton-pack: Add new CPUs 'k' values for branch mitigation (bsc#1242778).
• arm64: proton-pack: Expose whether the branchy loop k value (bsc#1242778).
• arm64: proton-pack: Expose whether the platform is mitigated by firmware (bsc#1242778).
• hv_netvsc: Preserve contiguous PFN grouping in the page buffer array (bsc#1243737).
• hv_netvsc: Remove rmsg_pgcnt (bsc#1243737).
• hv_netvsc: Use vmbus_sendpacket_mpb_desc() to send VMBus messages (bsc#1243737).
• mtd: phram: Add the kernel lock down check (bsc#1232649).
• net :mana :Add remaining GDMA stats for MANA to ethtool (bsc#1234395).
• net :mana :Request a V2 response version for MANA_QUERY_GF_STAT (bsc#1234395).
• net: mana: Add gdma stats to ethtool output for mana (bsc#1234395).
• nvme-pci: acquire cq_poll_lock in nvme_poll_irqdisable (bsc#1223096).
• ocfs2: fix the issue with discontiguous allocation in the global_bitmap (git-fixes).
• powerpc/pseries/iommu: IOMMU incorrectly marks MMIO range in DDW (bsc#1218470 ltc#204531).
• rpm/kernel-binary.spec.in: Also order against update-bootloader (boo#1228659, boo#1240785, boo#1241038).
• rpm/kernel-binary.spec.in: Fix missing 20-kernel-default-extra.conf (bsc#1239986)
• rpm/kernel-binary.spec.in: fix KMPs build on 6.13+ (bsc#1234454)
• rpm/kernel-docs.spec.in: Workaround for reproducible builds (bsc#1238303)
• rpm/release-projects: Update the ALP projects again (bsc#1231293).
• rpm/split-modules: Fix optional splitting with usrmerge (bsc#1238570)
• scsi: core: Fix unremoved procfs host directory regression (git-fixes).
• tcp: Dump bound-only sockets in inet_diag (bsc#1204562).
• tpm, tpm_tis: Workaround failed command reception on Infineon devices (bsc#1235870).
• tpm: tis: Double the timeout B to 4s (bsc#1235870).
• x86/bhi: Do not set BHI_DIS_S in 32-bit mode (bsc#1242778).
• x86/bpf: Add IBHF call at end of classic BPF (bsc#1242778).
• x86/bpf: Call branch history clearing sequence on exit (bsc#1242778).