Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

86f84779 · Linus Torvalds <[email protected]> · 2018-03-06 12:41:30 -08:00

Pull sigingo fix from Eric Biederman:
 "The kbuild test robot found that I accidentally moved si_pkey when I
  was cleaning up siginfo_t. A short followed by an int with the int
  having 8 byte alignment. Sheesh siginfo_t is a weird structure.

  I have now corrected it and added build time checks that with a little
  luck will catch any similar future mistakes. The build time checks
  were sufficient for me to verify the bug and to verify my fix. So they
  are at least useful this once."

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal/x86: Include the field offsets in the build time checks
  signal: Correct the offset of si_pkey in struct siginfo

Commit: 86f84779d8e92a690b2f281175ea06b884cb6fa4
Parents: ce380619 · f6a01549

Merge commit. Changes below are compared with the first parent: ce380619.

Changes

3 files changed · +69 −4

File	Status	Add	Del	Content
arch/x86/kernel/signal_compat.c	modified	+65	−0	View file
include/linux/compat.h	modified	+2	−2	View file
include/uapi/asm-generic/siginfo.h	modified	+2	−2	View file

arch/x86/kernel/signal_compat.c

View file

diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c
index ac057f9..0d930d8 100644
--- a/arch/x86/kernel/signal_compat.c
+++ b/arch/x86/kernel/signal_compat.c
@@ -43,6 +43,13 @@ static inline void signal_compat_build_tests(void)
 	BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields) != 3 * sizeof(int));
 #define CHECK_CSI_OFFSET(name)	  BUILD_BUG_ON(_sifields_offset != offsetof(compat_siginfo_t, _sifields.name))
 
+	BUILD_BUG_ON(offsetof(siginfo_t, si_signo) != 0);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_errno) != 4);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_code)  != 8);
+
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_signo) != 0);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_errno) != 4);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_code)  != 8);
 	 /*
 	 * Ensure that the size of each si_field never changes.
 	 * If it does, it is a sign that the
@@ -63,36 +70,94 @@ static inline void signal_compat_build_tests(void)
 	CHECK_CSI_SIZE  (_kill, 2*sizeof(int));
 	CHECK_SI_SIZE   (_kill, 2*sizeof(int));
 
+	BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x10);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x14);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid) != 0xC);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid) != 0x10);
+
 	CHECK_CSI_OFFSET(_timer);
 	CHECK_CSI_SIZE  (_timer, 3*sizeof(int));
 	CHECK_SI_SIZE   (_timer, 6*sizeof(int));
 
+	BUILD_BUG_ON(offsetof(siginfo_t, si_tid)     != 0x10);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_overrun) != 0x14);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_value)   != 0x18);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_tid)     != 0x0C);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_overrun) != 0x10);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_value)   != 0x14);
+
 	CHECK_CSI_OFFSET(_rt);
 	CHECK_CSI_SIZE  (_rt, 3*sizeof(int));
 	CHECK_SI_SIZE   (_rt, 4*sizeof(int));
 
+	BUILD_BUG_ON(offsetof(siginfo_t, si_pid)   != 0x10);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_uid)   != 0x14);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x18);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid)   != 0x0C);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid)   != 0x10);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_value) != 0x14);
+
 	CHECK_CSI_OFFSET(_sigchld);
 	CHECK_CSI_SIZE  (_sigchld, 5*sizeof(int));
 	CHECK_SI_SIZE   (_sigchld, 8*sizeof(int));
 
+	BUILD_BUG_ON(offsetof(siginfo_t, si_pid)    != 0x10);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_uid)    != 0x14);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_status) != 0x18);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_utime)  != 0x20);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_stime)  != 0x28);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid)    != 0x0C);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid)    != 0x10);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_status) != 0x14);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_utime)  != 0x18);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_stime)  != 0x1C);
+
 #ifdef CONFIG_X86_X32_ABI
 	CHECK_CSI_OFFSET(_sigchld_x32);
 	CHECK_CSI_SIZE  (_sigchld_x32, 7*sizeof(int));
 	/* no _sigchld_x32 in the generic siginfo_t */
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields._sigchld_x32._utime)  != 0x18);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields._sigchld_x32._stime)  != 0x20);
 #endif
 
 	CHECK_CSI_OFFSET(_sigfault);
 	CHECK_CSI_SIZE  (_sigfault, 4*sizeof(int));
 	CHECK_SI_SIZE   (_sigfault, 8*sizeof(int));
 
+	BUILD_BUG_ON(offsetof(siginfo_t, si_addr) != 0x10);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_addr) != 0x0C);
+
+	BUILD_BUG_ON(offsetof(siginfo_t, si_addr_lsb) != 0x18);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_addr_lsb) != 0x10);
+
+	BUILD_BUG_ON(offsetof(siginfo_t, si_lower) != 0x20);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_upper) != 0x28);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_lower) != 0x14);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_upper) != 0x18);
+
+	BUILD_BUG_ON(offsetof(siginfo_t, si_pkey) != 0x20);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pkey) != 0x14);
+
 	CHECK_CSI_OFFSET(_sigpoll);
 	CHECK_CSI_SIZE  (_sigpoll, 2*sizeof(int));
 	CHECK_SI_SIZE   (_sigpoll, 4*sizeof(int));
 
+	BUILD_BUG_ON(offsetof(siginfo_t, si_band)   != 0x10);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_fd)     != 0x18);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_band) != 0x0C);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_fd)   != 0x10);
+
 	CHECK_CSI_OFFSET(_sigsys);
 	CHECK_CSI_SIZE  (_sigsys, 3*sizeof(int));
 	CHECK_SI_SIZE   (_sigsys, 4*sizeof(int));
 
+	BUILD_BUG_ON(offsetof(siginfo_t, si_call_addr) != 0x10);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_syscall)   != 0x18);
+	BUILD_BUG_ON(offsetof(siginfo_t, si_arch)      != 0x1C);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_call_addr) != 0x0C);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_syscall)   != 0x10);
+	BUILD_BUG_ON(offsetof(compat_siginfo_t, si_arch)      != 0x14);
+
 	/* any new si_fields should be added here */
 }
 

include/linux/compat.h

View file

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 8a96438..e16d07e 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -229,13 +229,13 @@ typedef struct compat_siginfo {
 				short int _addr_lsb;	/* Valid LSB of the reported address. */
 				/* used when si_code=SEGV_BNDERR */
 				struct {
-					short _dummy_bnd;
+					compat_uptr_t _dummy_bnd;
 					compat_uptr_t _lower;
 					compat_uptr_t _upper;
 				} _addr_bnd;
 				/* used when si_code=SEGV_PKUERR */
 				struct {
-					short _dummy_pkey;
+					compat_uptr_t _dummy_pkey;
 					u32 _pkey;
 				} _addr_pkey;
 			};

include/uapi/asm-generic/siginfo.h

View file

diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index 85dc965..99c902e 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h
@@ -102,13 +102,13 @@ typedef struct siginfo {
 				short _addr_lsb; /* LSB of the reported address */
 				/* used when si_code=SEGV_BNDERR */
 				struct {
-					short _dummy_bnd;
+					void *_dummy_bnd;
 					void __user *_lower;
 					void __user *_upper;
 				} _addr_bnd;
 				/* used when si_code=SEGV_PKUERR */
 				struct {
-					short _dummy_pkey;
+					void *_dummy_pkey;
 					__u32 _pkey;
 				} _addr_pkey;
 			};