Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: XArray: Fix xas_create_range() when multi-order entry present If there is already an entry present that is of order >= XA_CHUNK_SHIFT when we call xas_create_range(), xas_create_range() will misinterpret that entry as a node and dereference xa_node->parent, generally leading to a crash that looks something like this: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 PID: 32 Comm: khugepaged Not tainted 5.17.0-rc8-syzkaller-00003-g56e337f2cf13 #0 RIP: 0010:xa_parent_locked include/linux/xarray.h:1207 [inline] RIP: 0010:xas_create_range+0x2d9/0x6e0 lib/xarray.c:725 It's deterministically reproducable once you know what the problem is, but producing it in a live kernel requires khugepaged to hit a race. While the problem has been present since xas_create_range() was introduced, I'm not aware of a way to hit it before the page cache was converted to use multi-index entries.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 6b24ca4a1a8d4ee3221d6d44ddbb99f542e4bda3 before 18f13edf3424b3b61814b69d5269b2e14584800c; affected 6b24ca4a1a8d4ee3221d6d44ddbb99f542e4bda3 before 3e3c658055c002900982513e289398a1aad4a488 |
| Linux / Linux | affected 5.17; unaffected 0 before 5.17; unaffected 5.17.2 through 5.17.*; unaffected 5.18 through * |
CWE
No CWE identifiers supplied.