Messages in this thread Patch in this message | | | From | Jialiang Wang <> | Subject | [PATCH] nfp: fix use-after-free in area_cache_get() | Date | Sat, 6 Aug 2022 22:30:43 +0800 |
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area_cache_get() calls cpp->op->area_init() and uses cache->area by nfp_cpp_area_priv(area), but in nfp_cpp_area_release()->nfp_cpp_area_put()->__release_cpp_area() we already freed the cache->area.
To avoid the use-after-free, reallocate a piece of memory for the cache->area by nfp_cpp_area_alloc().
Note: This vulnerability is triggerable by providing emulated device equipped with specified configuration.
BUG: KASAN: use-after-free in nfp6000_area_init+0x74/0x1d0 [nfp] Write of size 4 at addr ffff888005b490a0 by task insmod/226 Call Trace: <TASK> dump_stack_lvl+0x33/0x46 print_report.cold.12+0xb2/0x6b7 ? nfp6000_area_init+0x74/0x1d0 [nfp] kasan_report+0xa5/0x120 ? nfp6000_area_init+0x74/0x1d0 [nfp] nfp6000_area_init+0x74/0x1d0 [nfp] area_cache_get.constprop.8+0x2da/0x360 [nfp]
Signed-off-by: Jialiang Wang <wangjialiang0806@163.com> --- drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c index 34c0d2ddf9ef..99091f24d2ba 100644 --- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c +++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c @@ -871,6 +871,10 @@ area_cache_get(struct nfp_cpp *cpp, u32 id, nfp_cpp_area_release(cache->area); cache->id = 0; cache->addr = 0; + cache->area = nfp_cpp_area_alloc(cpp, + NFP_CPP_ID(7, + NFP_CPP_ACTION_RW, 0), + 0, cache->size); } /* Adjust the start address to be cache size aligned */ -- 2.17.1
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