[PATCH] uprobes: fix kernel info leak via "[uprobes]" vma

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



xol_add_vma() maps the uninitialized page allocated by __create_xol_area()
into userspace. On some architectures (x86) this memory is readable even
without VM_READ, VM_EXEC results in the same pgprot_t as VM_EXEC|VM_READ,
although this doesn't really matter, debugger can read this memory anyway.

Link: https://lore.kernel.org/all/20240929162047.GA12611@xxxxxxxxxx/

Reported-by: Will Deacon <will@xxxxxxxxxx>
Fixes: d4b3b6384f98 ("uprobes/core: Allocate XOL slots for uprobes use")
Cc: stable@xxxxxxxxxxxxxxx
Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Signed-off-by: Oleg Nesterov <oleg@xxxxxxxxxx>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>

diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 2ec796e2f055..4b52cb2ae6d6 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -1545,7 +1545,7 @@ static struct xol_area *__create_xol_area(unsigned long vaddr)
 	if (!area->bitmap)
 		goto free_area;
 
-	area->page = alloc_page(GFP_HIGHUSER);
+	area->page = alloc_page(GFP_HIGHUSER | __GFP_ZERO);
 	if (!area->page)
 		goto free_bitmap;
 





[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux