On Wed, Feb 12, 2025 at 04:15:03PM +0800, GONG Ruiqi wrote: > Hi, > > v3: > - move all the way from kmalloc_gfp_adjust to kvrealloc_noprof into > mm/slub.c > - some rewording for commit logs > v2: https://lore.kernel.org/all/20250208014723.1514049-1-gongruiqi1@xxxxxxxxxx/ > - change the implementation as Vlastimil suggested > v1: https://lore.kernel.org/all/20250122074817.991060-1-gongruiqi1@xxxxxxxxxx/ > > Tamás reported [1] that kmalloc cache randomization doesn't actually > work for those kmalloc invoked via kvmalloc. For more details, see the > commit log of patch 2. > > The current solution requires a direct call from __kvmalloc_node_noprof > to __do_kmalloc_node, a static function in a different .c file. As > suggested by Vlastimil [2], it's achieved by simply moving > __kvmalloc_node_noprof from mm/util.c to mm/slub.c, together with some > other functions of the same family. Hi, GONG! Sorry for my late review. This patch series looks good to me (with a nit), Reviewed-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx> Also, I verified that the problem you described exists on slab/for-next, and the patch series fixes the problem. Please feel free to add, Tested-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx> nit: Does it make sense to call __kvmalloc_node_track_caller_noprof() instead of __do_kmalloc_node() to avoid bloating the code size? My simple build test says it saves 1592 bytes: $ ./scripts/bloat-o-meter slub.o.before slub.o.after add/remove: 0/1 grow/shrink: 0/1 up/down: 0/-1592 (-1592) Function old new delta __kvmalloc_node_noprof.cold 39 - -39 __kvmalloc_node_noprof 1755 202 -1553 Total: Before=79723, After=78131, chg -2.00% > Link: https://github.com/google/security-research/blob/908d59b573960dc0b90adda6f16f7017aca08609/pocs/linux/kernelctf/CVE-2024-27397_mitigation/docs/exploit.md?plain=1#L259 [1] > Link: https://lore.kernel.org/all/62044279-0c56-4185-97f7-7afac65ff449@xxxxxxx/ [2] -- Harry
