CVE-2024-38661

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> s390/ap: Fix crash in AP internal function modify_bitmap()<br /> <br /> A system crash like this<br /> <br /> Failing address: 200000cb7df6f000 TEID: 200000cb7df6f403<br /> Fault in home space mode while using kernel ASCE.<br /> AS:00000002d71bc007 R3:00000003fe5b8007 S:000000011a446000 P:000000015660c13d<br /> Oops: 0038 ilc:3 [#1] PREEMPT SMP<br /> Modules linked in: mlx5_ib ...<br /> CPU: 8 PID: 7556 Comm: bash Not tainted 6.9.0-rc7 #8<br /> Hardware name: IBM 3931 A01 704 (LPAR)<br /> Krnl PSW : 0704e00180000000 0000014b75e7b606 (ap_parse_bitmap_str+0x10e/0x1f8)<br /> R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3<br /> Krnl GPRS: 0000000000000001 ffffffffffffffc0 0000000000000001 00000048f96b75d3<br /> 000000cb00000100 ffffffffffffffff ffffffffffffffff 000000cb7df6fce0<br /> 000000cb7df6fce0 00000000ffffffff 000000000000002b 00000048ffffffff<br /> 000003ff9b2dbc80 200000cb7df6fcd8 0000014bffffffc0 000000cb7df6fbc8<br /> Krnl Code: 0000014b75e7b5fc: a7840047 brc 8,0000014b75e7b68a<br /> 0000014b75e7b600: 18b2 lr %r11,%r2<br /> #0000014b75e7b602: a7f4000a brc 15,0000014b75e7b616<br /> &gt;0000014b75e7b606: eb22d00000e6 laog %r2,%r2,0(%r13)<br /> 0000014b75e7b60c: a7680001 lhi %r6,1<br /> 0000014b75e7b610: 187b lr %r7,%r11<br /> 0000014b75e7b612: 84960021 brxh %r9,%r6,0000014b75e7b654<br /> 0000014b75e7b616: 18e9 lr %r14,%r9<br /> Call Trace:<br /> [] ap_parse_bitmap_str+0x10e/0x1f8<br /> ([] ap_parse_bitmap_str+0xe4/0x1f8)<br /> [] apmask_store+0x68/0x140<br /> [] kernfs_fop_write_iter+0x14e/0x1e8<br /> [] vfs_write+0x1b4/0x448<br /> [] ksys_write+0x74/0x100<br /> [] __do_syscall+0x268/0x328<br /> [] system_call+0x70/0x98<br /> INFO: lockdep is turned off.<br /> Last Breaking-Event-Address:<br /> [] ap_parse_bitmap_str+0x13e/0x1f8<br /> Kernel panic - not syncing: Fatal exception: panic_on_oops<br /> <br /> occured when /sys/bus/ap/a[pq]mask was updated with a relative mask value<br /> (like +0x10-0x12,+60,-90) with one of the numeric values exceeding INT_MAX.<br /> <br /> The fix is simple: use unsigned long values for the internal variables. The<br /> correct checks are already in place in the function but a simple int for<br /> the internal variables was used with the possibility to overflow.