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c275c5c6d5
Poisoning freed pages protects against kernel use-after-free. The likelihood of such a bug involving kernel pages is significantly higher than that for user pages. At the same time, poisoning freed pages can impose a significant performance cost, which cannot always be justified for user pages given the lower probability of finding a bug. Therefore, disable freed user page poisoning when using HW tags. We identify "user" pages via the flag set GFP_HIGHUSER_MOVABLE, which indicates a strong likelihood of not being directly accessible to the kernel. Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Link: https://linux-review.googlesource.com/id/I716846e2de8ef179f44e835770df7e6307be96c9 Link: https://lore.kernel.org/r/20210602235230.3928842-5-pcc@google.com Signed-off-by: Will Deacon <will@kernel.org> |
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| .. | ||
| common.c | ||
| generic.c | ||
| hw_tags.c | ||
| init.c | ||
| kasan.h | ||
| Makefile | ||
| quarantine.c | ||
| report.c | ||
| report_generic.c | ||
| report_hw_tags.c | ||
| report_sw_tags.c | ||
| shadow.c | ||
| sw_tags.c | ||