CVE-2025-40349

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> hfs: validate record offset in hfsplus_bmap_alloc<br /> <br /> hfsplus_bmap_alloc can trigger a crash if a<br /> record offset or length is larger than node_size<br /> <br /> [ 15.264282] BUG: KASAN: slab-out-of-bounds in hfsplus_bmap_alloc+0x887/0x8b0<br /> [ 15.265192] Read of size 8 at addr ffff8881085ca188 by task test/183<br /> [ 15.265949]<br /> [ 15.266163] CPU: 0 UID: 0 PID: 183 Comm: test Not tainted 6.17.0-rc2-gc17b750b3ad9 #14 PREEMPT(voluntary)<br /> [ 15.266165] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014<br /> [ 15.266167] Call Trace:<br /> [ 15.266168] <br /> [ 15.266169] dump_stack_lvl+0x53/0x70<br /> [ 15.266173] print_report+0xd0/0x660<br /> [ 15.266181] kasan_report+0xce/0x100<br /> [ 15.266185] hfsplus_bmap_alloc+0x887/0x8b0<br /> [ 15.266208] hfs_btree_inc_height.isra.0+0xd5/0x7c0<br /> [ 15.266217] hfsplus_brec_insert+0x870/0xb00<br /> [ 15.266222] __hfsplus_ext_write_extent+0x428/0x570<br /> [ 15.266225] __hfsplus_ext_cache_extent+0x5e/0x910<br /> [ 15.266227] hfsplus_ext_read_extent+0x1b2/0x200<br /> [ 15.266233] hfsplus_file_extend+0x5a7/0x1000<br /> [ 15.266237] hfsplus_get_block+0x12b/0x8c0<br /> [ 15.266238] __block_write_begin_int+0x36b/0x12c0<br /> [ 15.266251] block_write_begin+0x77/0x110<br /> [ 15.266252] cont_write_begin+0x428/0x720<br /> [ 15.266259] hfsplus_write_begin+0x51/0x100<br /> [ 15.266262] cont_write_begin+0x272/0x720<br /> [ 15.266270] hfsplus_write_begin+0x51/0x100<br /> [ 15.266274] generic_perform_write+0x321/0x750<br /> [ 15.266285] generic_file_write_iter+0xc3/0x310<br /> [ 15.266289] __kernel_write_iter+0x2fd/0x800<br /> [ 15.266296] dump_user_range+0x2ea/0x910<br /> [ 15.266301] elf_core_dump+0x2a94/0x2ed0<br /> [ 15.266320] vfs_coredump+0x1d85/0x45e0<br /> [ 15.266349] get_signal+0x12e3/0x1990<br /> [ 15.266357] arch_do_signal_or_restart+0x89/0x580<br /> [ 15.266362] irqentry_exit_to_user_mode+0xab/0x110<br /> [ 15.266364] asm_exc_page_fault+0x26/0x30<br /> [ 15.266366] RIP: 0033:0x41bd35<br /> [ 15.266367] Code: bc d1 f3 0f 7f 27 f3 0f 7f 6f 10 f3 0f 7f 77 20 f3 0f 7f 7f 30 49 83 c0 0f 49 29 d0 48 8d 7c 17 31 e9 9f 0b 00 00 66 0f ef c0 0f 6f 0e f3 0f 6f 56 10 66 0f 74 c1 66 0f d7 d0 49 83 f8f<br /> [ 15.266369] RSP: 002b:00007ffc9e62d078 EFLAGS: 00010283<br /> [ 15.266371] RAX: 00007ffc9e62d100 RBX: 0000000000000000 RCX: 0000000000000000<br /> [ 15.266372] RDX: 00000000000000e0 RSI: 0000000000000000 RDI: 00007ffc9e62d100<br /> [ 15.266373] RBP: 0000400000000040 R08: 00000000000000e0 R09: 0000000000000000<br /> [ 15.266374] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000<br /> [ 15.266375] R13: 0000000000000000 R14: 0000000000000000 R15: 0000400000000000<br /> [ 15.266376] <br /> <br /> When calling hfsplus_bmap_alloc to allocate a free node, this function<br /> first retrieves the bitmap from header node and map node using node-&gt;page<br /> together with the offset and length from hfs_brec_lenoff<br /> <br /> ```<br /> len = hfs_brec_lenoff(node, 2, &amp;off16);<br /> off = off16;<br /> <br /> off += node-&gt;page_offset;<br /> pagep = node-&gt;page + (off &gt;&gt; PAGE_SHIFT);<br /> data = kmap_local_page(*pagep);<br /> ```<br /> <br /> However, if the retrieved offset or length is invalid(i.e. exceeds<br /> node_size), the code may end up accessing pages outside the allocated<br /> range for this node.<br /> <br /> This patch adds proper validation of both offset and length before use,<br /> preventing out-of-bounds page access. Move is_bnode_offset_valid and<br /> check_and_correct_requested_length to hfsplus_fs.h, as they may be<br /> required by other functions.