diff options
| author | Suresh Siddha <suresh.b.siddha@intel.com> | 2005-06-21 17:14:32 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-06-21 18:46:12 -0700 |
| commit | 84929801e14d968caeb84795bfbb88f04283fbd9 (patch) | |
| tree | 248fa9fd6cfb411a6df3b7f7fb42aa4f9ceca2bf /arch/x86_64/kernel/ptrace.c | |
| parent | 589777eab7360894b7ca1c4ba9d252e03b51225b (diff) | |
[PATCH] x86_64: TASK_SIZE fixes for compatibility mode processes
Appended patch will setup compatibility mode TASK_SIZE properly. This will
fix atleast three known bugs that can be encountered while running
compatibility mode apps.
a) A malicious 32bit app can have an elf section at 0xffffe000. During
exec of this app, we will have a memory leak as insert_vm_struct() is
not checking for return value in syscall32_setup_pages() and thus not
freeing the vma allocated for the vsyscall page. And instead of exec
failing (as it has addresses > TASK_SIZE), we were allowing it to
succeed previously.
b) With a 32bit app, hugetlb_get_unmapped_area/arch_get_unmapped_area
may return addresses beyond 32bits, ultimately causing corruption
because of wrap-around and resulting in SEGFAULT, instead of returning
ENOMEM.
c) 32bit app doing this below mmap will now fail.
mmap((void *)(0xFFFFE000UL), 0x10000UL, PROT_READ|PROT_WRITE,
MAP_FIXED|MAP_PRIVATE|MAP_ANON, 0, 0);
Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/x86_64/kernel/ptrace.c')
| -rw-r--r-- | arch/x86_64/kernel/ptrace.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/arch/x86_64/kernel/ptrace.c b/arch/x86_64/kernel/ptrace.c index 525f6a128a2..bbf64b59a21 100644 --- a/arch/x86_64/kernel/ptrace.c +++ b/arch/x86_64/kernel/ptrace.c @@ -257,12 +257,12 @@ static int putreg(struct task_struct *child, value &= 0xffff; return 0; case offsetof(struct user_regs_struct,fs_base): - if (value >= TASK_SIZE) + if (value >= TASK_SIZE_OF(child)) return -EIO; child->thread.fs = value; return 0; case offsetof(struct user_regs_struct,gs_base): - if (value >= TASK_SIZE) + if (value >= TASK_SIZE_OF(child)) return -EIO; child->thread.gs = value; return 0; @@ -279,7 +279,7 @@ static int putreg(struct task_struct *child, break; case offsetof(struct user_regs_struct, rip): /* Check if the new RIP address is canonical */ - if (value >= TASK_SIZE) + if (value >= TASK_SIZE_OF(child)) return -EIO; break; } @@ -419,6 +419,8 @@ asmlinkage long sys_ptrace(long request, long pid, unsigned long addr, long data break; case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ + { + int dsize = test_tsk_thread_flag(child, TIF_IA32) ? 3 : 7; ret = -EIO; if ((addr & 7) || addr > sizeof(struct user) - 7) @@ -430,22 +432,22 @@ asmlinkage long sys_ptrace(long request, long pid, unsigned long addr, long data break; /* Disallows to set a breakpoint into the vsyscall */ case offsetof(struct user, u_debugreg[0]): - if (data >= TASK_SIZE-7) break; + if (data >= TASK_SIZE_OF(child) - dsize) break; child->thread.debugreg0 = data; ret = 0; break; case offsetof(struct user, u_debugreg[1]): - if (data >= TASK_SIZE-7) break; + if (data >= TASK_SIZE_OF(child) - dsize) break; child->thread.debugreg1 = data; ret = 0; break; case offsetof(struct user, u_debugreg[2]): - if (data >= TASK_SIZE-7) break; + if (data >= TASK_SIZE_OF(child) - dsize) break; child->thread.debugreg2 = data; ret = 0; break; case offsetof(struct user, u_debugreg[3]): - if (data >= TASK_SIZE-7) break; + if (data >= TASK_SIZE_OF(child) - dsize) break; child->thread.debugreg3 = data; ret = 0; break; @@ -469,6 +471,7 @@ asmlinkage long sys_ptrace(long request, long pid, unsigned long addr, long data break; } break; + } case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ case PTRACE_CONT: /* restart after signal. */ |