6.6-stable review patch. If anyone has any objections, please let me know.
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From: Ewan D. Milne emilne@redhat.com
commit d8b90d600aff181936457f032d116dbd8534db06 upstream.
When scanning namespaces, it is possible to get valid data from the first call to nvme_identify_ns() in nvme_alloc_ns(), but not from the second call in nvme_update_ns_info_block(). In particular, if the NSID becomes inactive between the two commands, a storage device may return a buffer filled with zero as per 4.1.5.1. In this case, we can get a kernel crash due to a divide-by-zero in blk_stack_limits() because ns->lba_shift will be set to zero.
PID: 326 TASK: ffff95fec3cd8000 CPU: 29 COMMAND: "kworker/u98:10" #0 [ffffad8f8702f9e0] machine_kexec at ffffffff91c76ec7 #1 [ffffad8f8702fa38] __crash_kexec at ffffffff91dea4fa #2 [ffffad8f8702faf8] crash_kexec at ffffffff91deb788 #3 [ffffad8f8702fb00] oops_end at ffffffff91c2e4bb #4 [ffffad8f8702fb20] do_trap at ffffffff91c2a4ce #5 [ffffad8f8702fb70] do_error_trap at ffffffff91c2a595 #6 [ffffad8f8702fbb0] exc_divide_error at ffffffff928506e6 #7 [ffffad8f8702fbd0] asm_exc_divide_error at ffffffff92a00926 [exception RIP: blk_stack_limits+434] RIP: ffffffff92191872 RSP: ffffad8f8702fc80 RFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff95efa0c91800 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 00000000ffffffff R8: ffff95fec7df35a8 R9: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffff95fed33c09a8 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #8 [ffffad8f8702fce0] nvme_update_ns_info_block at ffffffffc06d3533 [nvme_core] #9 [ffffad8f8702fd18] nvme_scan_ns at ffffffffc06d6fa7 [nvme_core]
This happened when the check for valid data was moved out of nvme_identify_ns() into one of the callers. Fix this by checking in both callers.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218186 Fixes: 0dd6fff2aad4 ("nvme: bring back auto-removal of deleted namespaces during sequential scan") Cc: stable@vger.kernel.org Signed-off-by: Ewan D. Milne emilne@redhat.com Signed-off-by: Keith Busch kbusch@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/nvme/host/core.c | 9 +++++++++ 1 file changed, 9 insertions(+)
--- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -2026,6 +2026,13 @@ static int nvme_update_ns_info_block(str if (ret) return ret;
+ if (id->ncap == 0) { + /* namespace not allocated or attached */ + info->is_removed = true; + ret = -ENODEV; + goto error; + } + blk_mq_freeze_queue(ns->disk->queue); lbaf = nvme_lbaf_index(id->flbas); ns->lba_shift = id->lbaf[lbaf].ds; @@ -2083,6 +2090,8 @@ out: set_bit(NVME_NS_READY, &ns->flags); ret = 0; } + +error: kfree(id); return ret; }