Description
In the Linux kernel, the following vulnerability has been resolved: mm: krealloc: Fix MTE false alarm in __do_krealloc This patch addresses an issue introduced by commit 1a83a716ec233 ("mm: krealloc: consider spare memory for __GFP_ZERO") which causes MTE (Memory Tagging Extension) to falsely report a slab-out-of-bounds error. The problem occurs when zeroing out spare memory in __do_krealloc. The original code only considered software-based KASAN and did not account for MTE. It does not reset the KASAN tag before calling memset, leading to a mismatch between the pointer tag and the memory tag, resulting in a false positive. Example of the error: ================================================================== swapper/0: BUG: KASAN: slab-out-of-bounds in __memset+0x84/0x188 swapper/0: Write at addr f4ffff8005f0fdf0 by task swapper/0/1 swapper/0: Pointer tag: [f4], memory tag: [fe] swapper/0: swapper/0: CPU: 4 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12. swapper/0: Hardware name: MT6991(ENG) (DT) swapper/0: Call trace: swapper/0: dump_backtrace+0xfc/0x17c swapper/0: show_stack+0x18/0x28 swapper/0: dump_stack_lvl+0x40/0xa0 swapper/0: print_report+0x1b8/0x71c swapper/0: kasan_report+0xec/0x14c swapper/0: __do_kernel_fault+0x60/0x29c swapper/0: do_bad_area+0x30/0xdc swapper/0: do_tag_check_fault+0x20/0x34 swapper/0: do_mem_abort+0x58/0x104 swapper/0: el1_abort+0x3c/0x5c swapper/0: el1h_64_sync_handler+0x80/0xcc swapper/0: el1h_64_sync+0x68/0x6c swapper/0: __memset+0x84/0x188 swapper/0: btf_populate_kfunc_set+0x280/0x3d8 swapper/0: __register_btf_kfunc_id_set+0x43c/0x468 swapper/0: register_btf_kfunc_id_set+0x48/0x60 swapper/0: register_nf_nat_bpf+0x1c/0x40 swapper/0: nf_nat_init+0xc0/0x128 swapper/0: do_one_initcall+0x184/0x464 swapper/0: do_initcall_level+0xdc/0x1b0 swapper/0: do_initcalls+0x70/0xc0 swapper/0: do_basic_setup+0x1c/0x28 swapper/0: kernel_init_freeable+0x144/0x1b8 swapper/0: kernel_init+0x20/0x1a8 swapper/0: ret_from_fork+0x10/0x20 ==================================================================
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
c383263ee82a01a5a9bc1a466025ccde39a38cae to < 8ebee7565effdeae6085458f8f8463363120a871affecteda543785856249a5ba8c20468098601c0c33b1224 to < d02492863023431c31f85d570f718433c22b9311affected44f79667fefd52945a44d2a57a2cd3c554d7f4e0 to < d43f1430d47c22a0727c05b6f156ed25fecdfeb4affectedf8767d10bcbc2529540eb906906c0058e15cd918 to < 486aeb5f1855c75dd810c25036134961bd2a6722affectede3a9fc1520a6606c6121aca8d6679c6b93de7fd8 to < 71548fada7ee0eb50cc6ccda82dff010c745f92caffected3e9a65a38706866bf93e19f5b4936465188add10 to < 3dfb40da84f26dd35dd9bbaf626a2424565b8406affected1a83a716ec233990e1fd5b6fbb1200ade63bf450 to < 704573851b51808b45dae2d62059d1d8189138a2affected73388659ef0eea51747350530afdeadf8809ce9caffected6.10.14 to < 6.11affected
Linux Linux
Default version status: unaffected
5.10.227 to < 5.10.230affected5.15.168 to < 5.15.173affected6.1.113 to < 6.1.118affected6.6.55 to < 6.6.62affected6.11.3 to < 6.11.9affected
References
- https://git.kernel.org/stable/c/8ebee7565effdeae6085458f8f8463363120a871 ↗
- https://git.kernel.org/stable/c/d02492863023431c31f85d570f718433c22b9311 ↗
- https://git.kernel.org/stable/c/d43f1430d47c22a0727c05b6f156ed25fecdfeb4 ↗
- https://git.kernel.org/stable/c/486aeb5f1855c75dd810c25036134961bd2a6722 ↗
- https://git.kernel.org/stable/c/71548fada7ee0eb50cc6ccda82dff010c745f92c ↗
- https://git.kernel.org/stable/c/3dfb40da84f26dd35dd9bbaf626a2424565b8406 ↗
- https://git.kernel.org/stable/c/704573851b51808b45dae2d62059d1d8189138a2 ↗
- https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html ↗
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html ↗