| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2021-47578: scsi: scsi_debug: Don't call kcalloc() if size arg is zero |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| scsi: scsi_debug: Don't call kcalloc() if size arg is zero |
| |
| If the size arg to kcalloc() is zero, it returns ZERO_SIZE_PTR. Because of |
| that, for a following NULL pointer check to work on the returned pointer, |
| kcalloc() must not be called with the size arg equal to zero. Return early |
| without error before the kcalloc() call if size arg is zero. |
| |
| BUG: KASAN: null-ptr-deref in memcpy include/linux/fortify-string.h:191 [inline] |
| BUG: KASAN: null-ptr-deref in sg_copy_buffer+0x138/0x240 lib/scatterlist.c:974 |
| Write of size 4 at addr 0000000000000010 by task syz-executor.1/22789 |
| |
| CPU: 1 PID: 22789 Comm: syz-executor.1 Not tainted 5.15.0-syzk #1 |
| Hardware name: Red Hat KVM, BIOS 1.13.0-2 |
| Call Trace: |
| __dump_stack lib/dump_stack.c:88 [inline] |
| dump_stack_lvl+0x89/0xb5 lib/dump_stack.c:106 |
| __kasan_report mm/kasan/report.c:446 [inline] |
| kasan_report.cold.14+0x112/0x117 mm/kasan/report.c:459 |
| check_region_inline mm/kasan/generic.c:183 [inline] |
| kasan_check_range+0x1a3/0x210 mm/kasan/generic.c:189 |
| memcpy+0x3b/0x60 mm/kasan/shadow.c:66 |
| memcpy include/linux/fortify-string.h:191 [inline] |
| sg_copy_buffer+0x138/0x240 lib/scatterlist.c:974 |
| do_dout_fetch drivers/scsi/scsi_debug.c:2954 [inline] |
| do_dout_fetch drivers/scsi/scsi_debug.c:2946 [inline] |
| resp_verify+0x49e/0x930 drivers/scsi/scsi_debug.c:4276 |
| schedule_resp+0x4d8/0x1a70 drivers/scsi/scsi_debug.c:5478 |
| scsi_debug_queuecommand+0x8c9/0x1ec0 drivers/scsi/scsi_debug.c:7533 |
| scsi_dispatch_cmd drivers/scsi/scsi_lib.c:1520 [inline] |
| scsi_queue_rq+0x16b0/0x2d40 drivers/scsi/scsi_lib.c:1699 |
| blk_mq_dispatch_rq_list+0xb9b/0x2700 block/blk-mq.c:1639 |
| __blk_mq_sched_dispatch_requests+0x28f/0x590 block/blk-mq-sched.c:325 |
| blk_mq_sched_dispatch_requests+0x105/0x190 block/blk-mq-sched.c:358 |
| __blk_mq_run_hw_queue+0xe5/0x150 block/blk-mq.c:1761 |
| __blk_mq_delay_run_hw_queue+0x4f8/0x5c0 block/blk-mq.c:1838 |
| blk_mq_run_hw_queue+0x18d/0x350 block/blk-mq.c:1891 |
| blk_mq_sched_insert_request+0x3db/0x4e0 block/blk-mq-sched.c:474 |
| blk_execute_rq_nowait+0x16b/0x1c0 block/blk-exec.c:62 |
| blk_execute_rq+0xdb/0x360 block/blk-exec.c:102 |
| sg_scsi_ioctl drivers/scsi/scsi_ioctl.c:621 [inline] |
| scsi_ioctl+0x8bb/0x15c0 drivers/scsi/scsi_ioctl.c:930 |
| sg_ioctl_common+0x172d/0x2710 drivers/scsi/sg.c:1112 |
| sg_ioctl+0xa2/0x180 drivers/scsi/sg.c:1165 |
| vfs_ioctl fs/ioctl.c:51 [inline] |
| __do_sys_ioctl fs/ioctl.c:874 [inline] |
| __se_sys_ioctl fs/ioctl.c:860 [inline] |
| __x64_sys_ioctl+0x19d/0x220 fs/ioctl.c:860 |
| do_syscall_x64 arch/x86/entry/common.c:50 [inline] |
| do_syscall_64+0x3a/0x80 arch/x86/entry/common.c:80 |
| entry_SYSCALL_64_after_hwframe+0x44/0xae |
| |
| The Linux kernel CVE team has assigned CVE-2021-47578 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.10.88 with commit aa1f912712a109b6306746133de7e5343f016b26 |
| Fixed in 5.15.11 with commit 47d11d35203b0aa13533634e270fe2c3610e531b |
| Fixed in 5.16 with commit 3344b58b53a76199dae48faa396e9fc37bf86992 |
| |
| 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-2021-47578 |
| 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/scsi/scsi_debug.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/aa1f912712a109b6306746133de7e5343f016b26 |
| https://git.kernel.org/stable/c/47d11d35203b0aa13533634e270fe2c3610e531b |
| https://git.kernel.org/stable/c/3344b58b53a76199dae48faa396e9fc37bf86992 |
