mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2025-03-05 20:15:31 +07:00
5f16a046f8
FUTEX_OP_OPARG_SHIFT instructs the futex code to treat the 12-bit oparg field as a shift value, potentially leading to a left shift value that is negative or with an absolute value that is significantly larger then the size of the type. UBSAN chokes with: ================================================================================ UBSAN: Undefined behaviour in ./arch/arm64/include/asm/futex.h:60:13 shift exponent -1 is negative CPU: 1 PID: 1449 Comm: syz-executor0 Not tainted 4.11.0-rc4-00005-g977eb52-dirty #11 Hardware name: linux,dummy-virt (DT) Call trace: [<ffff200008094778>] dump_backtrace+0x0/0x538 arch/arm64/kernel/traps.c:73 [<ffff200008094cd0>] show_stack+0x20/0x30 arch/arm64/kernel/traps.c:228 [<ffff200008c194a8>] __dump_stack lib/dump_stack.c:16 [inline] [<ffff200008c194a8>] dump_stack+0x120/0x188 lib/dump_stack.c:52 [<ffff200008cc24b8>] ubsan_epilogue+0x18/0x98 lib/ubsan.c:164 [<ffff200008cc3098>] __ubsan_handle_shift_out_of_bounds+0x250/0x294 lib/ubsan.c:421 [<ffff20000832002c>] futex_atomic_op_inuser arch/arm64/include/asm/futex.h:60 [inline] [<ffff20000832002c>] futex_wake_op kernel/futex.c:1489 [inline] [<ffff20000832002c>] do_futex+0x137c/0x1740 kernel/futex.c:3231 [<ffff200008320504>] SYSC_futex kernel/futex.c:3281 [inline] [<ffff200008320504>] SyS_futex+0x114/0x268 kernel/futex.c:3249 [<ffff200008084770>] el0_svc_naked+0x24/0x28 ================================================================================ syz-executor1 uses obsolete (PF_INET,SOCK_PACKET) sock: process `syz-executor0' is using obsolete setsockopt SO_BSDCOMPAT This patch attempts to fix some of this by: * Making encoded_op an unsigned type, so we can shift it left even if the top bit is set. * Casting to signed prior to shifting right when extracting oparg and cmparg * Consider only the bottom 5 bits of oparg when using it as a left-shift value. Whilst I think this catches all of the issues, I'd much prefer to remove this stuff, as I think it's unused and the bugs are copy-pasted between a bunch of architectures. Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> |
||
|---|---|---|
| .. | ||
| alpha | ||
| arc | ||
| arm | ||
| arm64 | ||
| blackfin | ||
| c6x | ||
| cris | ||
| frv | ||
| h8300 | ||
| hexagon | ||
| ia64 | ||
| m32r | ||
| m68k | ||
| metag | ||
| microblaze | ||
| mips | ||
| mn10300 | ||
| nios2 | ||
| openrisc | ||
| parisc | ||
| powerpc | ||
| s390 | ||
| score | ||
| sh | ||
| sparc | ||
| tile | ||
| um | ||
| unicore32 | ||
| x86 | ||
| xtensa | ||
| .gitignore | ||
| Kconfig | ||