CVE-2024-44965
Beschrijving NL
In the Linux kernel, the following vulnerability has been resolved:
x86/mm: Fix pti_clone_pgtable() alignment assumption
Guenter reported dodgy crashes on an i386-nosmp build using GCC-11
that had the form of endless traps until entry stack exhaust and then
#DF from the stack guard. It turned out that pti_clone_pgtable() had alignment assumptions on
the start address, notably it hard assumes start is PMD aligned. This
is true on x86_64, but very much not true on i386. These assumptions can cause the end condition to malfunction, leading
to a 'short' clone. Guess what happens when the user mapping has a
short copy of the entry text? Use the correct increment form for addr to avoid alignment
assumptions.
Origineel (Engels) tonen
In the Linux kernel, the following vulnerability has been resolved:
x86/mm: Fix pti_clone_pgtable() alignment assumption
Guenter reported dodgy crashes on an i386-nosmp build using GCC-11
that had the form of endless traps until entry stack exhaust and then
#DF from the stack guard.
It turned out that pti_clone_pgtable() had alignment assumptions on
the start address, notably it hard assumes start is PMD aligned. This
is true on x86_64, but very much not true on i386.
These assumptions can cause the end condition to malfunction, leading
to a 'short' clone. Guess what happens when the user mapping has a
short copy of the entry text?
Use the correct increment form for addr to avoid alignment
assumptions.