From 1b2ce442ea96b1e76300553963154d68cc5b4ad0 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Sun, 24 Jul 2016 11:30:22 -0400 Subject: binfmt_flat: use proper user space accessors with old relocs code Signed-off-by: Nicolas Pitre Reviewed-by: Greg Ungerer Signed-off-by: Greg Ungerer --- fs/binfmt_flat.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) (limited to 'fs/binfmt_flat.c') diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index 9deafb282db5..8e812d7a62e0 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -379,35 +379,38 @@ static void old_reloc(unsigned long rl) { static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; flat_v2_reloc_t r; - unsigned long *ptr; + unsigned long __user *ptr; + unsigned long val; r.value = rl; #if defined(CONFIG_COLDFIRE) - ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset); + ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset); #else - ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset); + ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset); #endif + get_user(val, ptr); pr_debug("Relocation of variable at DATASEG+%x " "(address %p, currently %lx) into segment %s\n", - r.reloc.offset, ptr, *ptr, segment[r.reloc.type]); + r.reloc.offset, ptr, val, segment[r.reloc.type]); switch (r.reloc.type) { case OLD_FLAT_RELOC_TYPE_TEXT: - *ptr += current->mm->start_code; + val += current->mm->start_code; break; case OLD_FLAT_RELOC_TYPE_DATA: - *ptr += current->mm->start_data; + val += current->mm->start_data; break; case OLD_FLAT_RELOC_TYPE_BSS: - *ptr += current->mm->end_data; + val += current->mm->end_data; break; default: pr_err("Unknown relocation type=%x\n", r.reloc.type); break; } + put_user(val, ptr); - pr_debug("Relocation became %lx\n", *ptr); + pr_debug("Relocation became %lx\n", val); } /****************************************************************************/ @@ -780,8 +783,13 @@ static int load_flat_file(struct linux_binprm *bprm, } } } else { - for (i = 0; i < relocs; i++) - old_reloc(ntohl(reloc[i])); + for (i = 0; i < relocs; i++) { + unsigned long relval; + if (get_user(relval, reloc + i)) + return -EFAULT; + relval = ntohl(relval); + old_reloc(relval); + } } flush_icache_range(start_code, end_code); -- cgit v1.2.3