Affected: Alpaquita:23: linux-lts, Alpaquita:stream: linux-lts

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

s390/dcssblk: fix kernel crash with list_add corruption

Commit fb08a1908cb1 ("dax: simplify the dax_device <-> gendisk association") introduced new logic for gendisk association, requiring drivers to explicitly call dax_add_host() and dax_remove_host().

For dcssblk driver, some dax_remove_host() calls were missing, e.g. in device remove path. The commit also broke error handling for out_dax case in device add path, resulting in an extra put_device() w/o the previous get_device() in that case.

This lead to stale xarray entries after device add / remove cycles. In the case when a previously used struct gendisk pointer (xarray index) would be used again, because blk_alloc_disk() happened to return such a pointer, the xa_insert() in dax_add_host() would fail and go to out_dax, doing the extra put_device() in the error path. In combination with an already flawed error handling in dcssblk (device_register() cleanup), which needs to be addressed in a separate patch, this resulted in a missing device_del() / klist_del(), and eventually in the kernel crash with list_add corruption on a subsequent device_add() / klist_add().

Fix this by adding the missing dax_remove_host() calls, and also move the put_device() in the error path to restore the previous logic.

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

s390/dcssblk: fix kernel crash with list_add corruption

Commit fb08a1908cb1 ("dax: simplify the dax_device <-> gendisk association") introduced new logic for gendisk association, requiring drivers to explicitly call dax_add_host() and dax_remove_host().

For dcssblk driver, some dax_remove_host() calls were missing, e.g. in device remove path. The commit also broke error handling for out_dax case in device add path, resulting in an extra put_device() w/o the previous get_device() in that case.

This lead to stale xarray entries after device add / remove cycles. In the case when a previously used struct gendisk pointer (xarray index) would be used again, because blk_alloc_disk() happened to return such a pointer, the xa_insert() in dax_add_host() would fail and go to out_dax, doing the extra put_device() in the error path. In combination with an already flawed error handling in dcssblk (device_register() cleanup), which needs to be addressed in a separate patch, this resulted in a missing device_del() / klist_del(), and eventually in the kernel crash with list_add corruption on a subsequent device_add() / klist_add().

Fix this by adding the missing dax_remove_host() calls, and also move the put_device() in the error path to restore the previous logic.

kernel: xen-netfront: Fix NULL sring after live migration kernel: fscache: Fix oops due to race with cookie_lru and use_cookie kernel: tracing: Free buffers when a used dynamic event is removed kernel: net: tun: Fix use-after-free in tun_detach() kernel: hwmon: (ibmpex) Fix possible UAF when ibmpex_register_bmc() fails kernel: erofs/zmap.c: Fix incorrect offset calculation kernel: arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud kernel: s390: avoid using global register for current_stack_pointer kernel: erofs: fix missing xas_retry() in fscache mode kernel: rpmsg: qcom_smd: Fix refcount leak in qcom_smd_parse_edge kernel: remoteproc: k3-r5: Fix refcount leak in k3_r5_cluster_of_init kernel: of: check previous kernel's ima-kexec-buffer against memory bounds kernel: coresight: Clear the connection field properly kernel: Linux kernel: Denial of Service in coresight: trbe kernel: rpmsg: char: Avoid double destroy of default endpoint kernel: coresight: cti: Fix hang in cti_disable_hw() kernel: lib/fonts: fix undefined behavior in bit shift for get_default_font kernel: Kernel: Denial of Service in pci_endpoint_test due to zero-length DMA mapping kernel: Linux kernel: Denial of Service in erofs due to memory leak kernel: erofs: fix missing unmap if z_erofs_get_extent_compressedlen() fails kernel: pipe: wakeup wr_wait after setting max_usage kernel: ntb: intel: Fix the NULL vs IS_ERR() bug for debugfs_create_dir() kernel: qed/qed_sriov: guard against NULL derefs from qed_…

Security update for the Linux Kernel

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 79 more

In the Linux kernel, the following vulnerability has been resolved: s390/dcssblk: fix kernel crash with list_add corruption Commit fb08a1908cb1 ("dax: simplify the dax_device <-> gendisk association") introduced new logic for gendisk association, requiring drivers to explicitly call dax_add_host() and dax_remove_host(). For dcssblk driver, some dax_remove_host() calls were missing, e.g. in device remove path. The commit also broke error handling for out_dax case in device add path, resulting in an extra put_device() w/o the previous get_device() in that case. This lead to stale xarray entries after device add / remove cycles. In the case when a previously used struct gendisk pointer (xarray index) would be used again, because blk_alloc_disk() happened to return such a pointer, the xa_insert() in dax_add_host() would fail and go to out_dax, doing the extra put_device() in the error path. In combination with an already flawed error handling in dcssblk (device_register() cleanup), which needs to be addressed in a separate patch, this resulted in a missing device_del() / klist_del(), and eventually in the kernel crash with list_add corruption on a subsequent device_add() / klist_add(). Fix this by adding the missing dax_remove_host() calls, and also move the put_device() in the error path to restore the previous logic.

Ein Angreifer kann mehrere Schwachstellen im Linux-Kernel ausnutzen, um nicht näher spezifizierte Angriffe durchzuführen, die möglicherweise zu einer Denial-of-Service- Bedingung führen oder eine Speicherbeschädigung verursachen können.