| From bippy-1.2.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-26957: s390/zcrypt: fix reference counting on zcrypt card objects |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| s390/zcrypt: fix reference counting on zcrypt card objects |
| |
| Tests with hot-plugging crytpo cards on KVM guests with debug |
| kernel build revealed an use after free for the load field of |
| the struct zcrypt_card. The reason was an incorrect reference |
| handling of the zcrypt card object which could lead to a free |
| of the zcrypt card object while it was still in use. |
| |
| This is an example of the slab message: |
| |
| kernel: 0x00000000885a7512-0x00000000885a7513 @offset=1298. First byte 0x68 instead of 0x6b |
| kernel: Allocated in zcrypt_card_alloc+0x36/0x70 [zcrypt] age=18046 cpu=3 pid=43 |
| kernel: kmalloc_trace+0x3f2/0x470 |
| kernel: zcrypt_card_alloc+0x36/0x70 [zcrypt] |
| kernel: zcrypt_cex4_card_probe+0x26/0x380 [zcrypt_cex4] |
| kernel: ap_device_probe+0x15c/0x290 |
| kernel: really_probe+0xd2/0x468 |
| kernel: driver_probe_device+0x40/0xf0 |
| kernel: __device_attach_driver+0xc0/0x140 |
| kernel: bus_for_each_drv+0x8c/0xd0 |
| kernel: __device_attach+0x114/0x198 |
| kernel: bus_probe_device+0xb4/0xc8 |
| kernel: device_add+0x4d2/0x6e0 |
| kernel: ap_scan_adapter+0x3d0/0x7c0 |
| kernel: ap_scan_bus+0x5a/0x3b0 |
| kernel: ap_scan_bus_wq_callback+0x40/0x60 |
| kernel: process_one_work+0x26e/0x620 |
| kernel: worker_thread+0x21c/0x440 |
| kernel: Freed in zcrypt_card_put+0x54/0x80 [zcrypt] age=9024 cpu=3 pid=43 |
| kernel: kfree+0x37e/0x418 |
| kernel: zcrypt_card_put+0x54/0x80 [zcrypt] |
| kernel: ap_device_remove+0x4c/0xe0 |
| kernel: device_release_driver_internal+0x1c4/0x270 |
| kernel: bus_remove_device+0x100/0x188 |
| kernel: device_del+0x164/0x3c0 |
| kernel: device_unregister+0x30/0x90 |
| kernel: ap_scan_adapter+0xc8/0x7c0 |
| kernel: ap_scan_bus+0x5a/0x3b0 |
| kernel: ap_scan_bus_wq_callback+0x40/0x60 |
| kernel: process_one_work+0x26e/0x620 |
| kernel: worker_thread+0x21c/0x440 |
| kernel: kthread+0x150/0x168 |
| kernel: __ret_from_fork+0x3c/0x58 |
| kernel: ret_from_fork+0xa/0x30 |
| kernel: Slab 0x00000372022169c0 objects=20 used=18 fp=0x00000000885a7c88 flags=0x3ffff00000000a00(workingset|slab|node=0|zone=1|lastcpupid=0x1ffff) |
| kernel: Object 0x00000000885a74b8 @offset=1208 fp=0x00000000885a7c88 |
| kernel: Redzone 00000000885a74b0: bb bb bb bb bb bb bb bb ........ |
| kernel: Object 00000000885a74b8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk |
| kernel: Object 00000000885a74c8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk |
| kernel: Object 00000000885a74d8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk |
| kernel: Object 00000000885a74e8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk |
| kernel: Object 00000000885a74f8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk |
| kernel: Object 00000000885a7508: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 68 4b 6b 6b 6b a5 kkkkkkkkkkhKkkk. |
| kernel: Redzone 00000000885a7518: bb bb bb bb bb bb bb bb ........ |
| kernel: Padding 00000000885a756c: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZ |
| kernel: CPU: 0 PID: 387 Comm: systemd-udevd Not tainted 6.8.0-HF #2 |
| kernel: Hardware name: IBM 3931 A01 704 (KVM/Linux) |
| kernel: Call Trace: |
| kernel: [<00000000ca5ab5b8>] dump_stack_lvl+0x90/0x120 |
| kernel: [<00000000c99d78bc>] check_bytes_and_report+0x114/0x140 |
| kernel: [<00000000c99d53cc>] check_object+0x334/0x3f8 |
| kernel: [<00000000c99d820c>] alloc_debug_processing+0xc4/0x1f8 |
| kernel: [<00000000c99d852e>] get_partial_node.part.0+0x1ee/0x3e0 |
| kernel: [<00000000c99d94ec>] ___slab_alloc+0xaf4/0x13c8 |
| kernel: [<00000000c99d9e38>] __slab_alloc.constprop.0+0x78/0xb8 |
| kernel: [<00000000c99dc8dc>] __kmalloc+0x434/0x590 |
| kernel: [<00000000c9b4c0ce>] ext4_htree_store_dirent+0x4e/0x1c0 |
| kernel: [<00000000c9b908a2>] htree_dirblock_to_tree+0x17a/0x3f0 |
| kernel: [<00000000c9b919dc>] ext4_htree_fill_tree+0x134/0x400 |
| kernel: [<00000000c9b4b3d0>] ext4_dx_readdir+0x160/0x2f0 |
| kernel: [<00000000c9b4bedc>] ext4_readdir+0x5f4/0x760 |
| kernel: [<00000000c9a7efc4>] iterate_dir+0xb4/0x280 |
| kernel: [<00000000c9a7f1ea>] __do_sys_getdents64+0x5a/0x120 |
| kernel: [<00000000ca5d6946>] __do_syscall+0x256/0x310 |
| kernel: [<00000000ca5eea10>] system_call+0x70/0x98 |
| kernel: INFO: lockdep is turned off. |
| kernel: FIX kmalloc-96: Restoring Poison 0x00000000885a7512-0x00000000885a7513=0x6b |
| kernel: FIX kmalloc-96: Marking all objects used |
| |
| The fix is simple: Before use of the queue not only the queue object |
| but also the card object needs to increase it's reference count |
| with a call to zcrypt_card_get(). Similar after use of the queue |
| not only the queue but also the card object's reference count is |
| decreased with zcrypt_card_put(). |
| |
| The Linux kernel CVE team has assigned CVE-2024-26957 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 4.19.312 with commit 7e500849fa558879a1cde43f80c7c048c2437058 |
| Fixed in 5.4.274 with commit 9daddee03de3f231012014dab8ab2b277a116a55 |
| Fixed in 5.10.215 with commit 6470078ab3d8f222115e11c4ec67351f3031b3dd |
| Fixed in 5.15.154 with commit a55677878b93e9ebc31f66d0e2fb93be5e7836a6 |
| Fixed in 6.1.84 with commit b7f6c3630eb3f103115ab0d7613588064f665d0d |
| Fixed in 6.6.24 with commit a64ab862e84e3e698cd351a87cdb504c7fc575ca |
| Fixed in 6.7.12 with commit befb7f889594d23e1b475720cf93efd2f77df000 |
| Fixed in 6.8.3 with commit 394b6d8bbdf9ddee6d5bcf3e1f3e9f23eecd6484 |
| Fixed in 6.9 with commit 50ed48c80fecbe17218afed4f8bed005c802976c |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-26957 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| drivers/s390/crypto/zcrypt_api.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/7e500849fa558879a1cde43f80c7c048c2437058 |
| https://git.kernel.org/stable/c/9daddee03de3f231012014dab8ab2b277a116a55 |
| https://git.kernel.org/stable/c/6470078ab3d8f222115e11c4ec67351f3031b3dd |
| https://git.kernel.org/stable/c/a55677878b93e9ebc31f66d0e2fb93be5e7836a6 |
| https://git.kernel.org/stable/c/b7f6c3630eb3f103115ab0d7613588064f665d0d |
| https://git.kernel.org/stable/c/a64ab862e84e3e698cd351a87cdb504c7fc575ca |
| https://git.kernel.org/stable/c/befb7f889594d23e1b475720cf93efd2f77df000 |
| https://git.kernel.org/stable/c/394b6d8bbdf9ddee6d5bcf3e1f3e9f23eecd6484 |
| https://git.kernel.org/stable/c/50ed48c80fecbe17218afed4f8bed005c802976c |
