From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> Subject: lib/list_debug.c: print unmangled addresses The entire point of printing the pointers in list_debug is to see if there's any useful information in them (eg poison values, ASCII, etc); obscuring them to see if they compare equal makes them much less useful. If an attacker can force this message to be printed, we've already lost. Link: http://lkml.kernel.org/r/20180401223237.GV13332@xxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> Reviewed-by: Tobin C. Harding <me@xxxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Eric Biggers <ebiggers3@xxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/list_debug.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff -puN lib/list_debug.c~list_debug-print-unmangled-addresses lib/list_debug.c --- a/lib/list_debug.c~list_debug-print-unmangled-addresses +++ a/lib/list_debug.c @@ -21,13 +21,13 @@ bool __list_add_valid(struct list_head * struct list_head *next) { if (CHECK_DATA_CORRUPTION(next->prev != prev, - "list_add corruption. next->prev should be prev (%p), but was %p. (next=%p).\n", + "list_add corruption. next->prev should be prev (%px), but was %px. (next=%px).\n", prev, next->prev, next) || CHECK_DATA_CORRUPTION(prev->next != next, - "list_add corruption. prev->next should be next (%p), but was %p. (prev=%p).\n", + "list_add corruption. prev->next should be next (%px), but was %px. (prev=%px).\n", next, prev->next, prev) || CHECK_DATA_CORRUPTION(new == prev || new == next, - "list_add double add: new=%p, prev=%p, next=%p.\n", + "list_add double add: new=%px, prev=%px, next=%px.\n", new, prev, next)) return false; @@ -43,16 +43,16 @@ bool __list_del_entry_valid(struct list_ next = entry->next; if (CHECK_DATA_CORRUPTION(next == LIST_POISON1, - "list_del corruption, %p->next is LIST_POISON1 (%p)\n", + "list_del corruption, %px->next is LIST_POISON1 (%px)\n", entry, LIST_POISON1) || CHECK_DATA_CORRUPTION(prev == LIST_POISON2, - "list_del corruption, %p->prev is LIST_POISON2 (%p)\n", + "list_del corruption, %px->prev is LIST_POISON2 (%px)\n", entry, LIST_POISON2) || CHECK_DATA_CORRUPTION(prev->next != entry, - "list_del corruption. prev->next should be %p, but was %p\n", + "list_del corruption. prev->next should be %px, but was %px\n", entry, prev->next) || CHECK_DATA_CORRUPTION(next->prev != entry, - "list_del corruption. next->prev should be %p, but was %p\n", + "list_del corruption. next->prev should be %px, but was %px\n", entry, next->prev)) return false; _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
