diff options
| author | Will Deacon <will.deacon@arm.com> | 2017-11-14 16:15:59 +0000 |
|---|---|---|
| committer | Jonathan Solnit <jsolnit@google.com> | 2018-01-12 09:11:59 -0800 |
| commit | 0d09a6d27ec35f4e0237192c4110b40a2dc67216 (patch) | |
| tree | 2f08cf6ec10d2f408b9ebb7d9da6c03ec6dda510 /lib/mpi/mpiutil.c | |
| parent | f50392b6f895d2ad847df5f1b213aa382ea89d04 (diff) | |
arm64: use RET instruction for exiting the trampoline
Speculation attacks against the entry trampoline can potentially resteer
the speculative instruction stream through the indirect branch and into
arbitrary gadgets within the kernel.
This patch defends against these attacks by forcing a misprediction
through the return stack: a dummy BL instruction loads an entry into
the stack, so that the predicted program flow of the subsequent RET
instruction is to a branch-to-self instruction which is finally resolved
as a branch to the kernel vectors with speculation suppressed.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Bug: 69856074
Change-Id: I08c24d7508f3759dbdd87a0549f8ccddb3e4c38b
Diffstat (limited to 'lib/mpi/mpiutil.c')
0 files changed, 0 insertions, 0 deletions