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Commit e30c7c3b authored by Takuya Yoshikawa's avatar Takuya Yoshikawa Committed by Linus Torvalds
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binfmt_elf_fdpic: Fix clear_user() error handling 



clear_user() returns the number of bytes that could not be copied rather than
an error code.  So we should return -EFAULT rather than directly returning the
results.

Without this patch, positive values may be returned to elf_fdpic_map_file()
and the following error handlings do not function as expected.

1.
	ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
	if (ret < 0)
		return ret;
2.
	ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
	if (ret < 0)
		return ret;

Signed-off-by: default avatarTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarMike Frysinger <vapier@gentoo.org>
CC: Alexander Viro <viro@zeniv.linux.org.uk>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
CC: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 293a7cfe

fs/binfmt_elf_fdpic.c

+11 −15
Original line number Diff line number Diff line
@@ -990,10 +990,9 @@ static int elf_fdpic_map_file_constdisp_on_uclinux( 


		/* clear any space allocated but not loaded */

		if (phdr->p_filesz < phdr->p_memsz) {

			ret = clear_user((void *) (seg->addr + phdr->p_filesz),

					 phdr->p_memsz - phdr->p_filesz);

			if (ret)

				return ret;

			if (clear_user((void *) (seg->addr + phdr->p_filesz),

				       phdr->p_memsz - phdr->p_filesz))

				return -EFAULT;

		}



		if (mm) {
@@ -1027,7 +1026,7 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 
	struct elf32_fdpic_loadseg *seg;

	struct elf32_phdr *phdr;

	unsigned long load_addr, delta_vaddr;

	int loop, dvset, ret;

	int loop, dvset;



	load_addr = params->load_addr;

	delta_vaddr = 0;
@@ -1127,9 +1126,8 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 
		 * PT_LOAD */

		if (prot & PROT_WRITE && disp > 0) {

			kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);

			ret = clear_user((void __user *) maddr, disp);

			if (ret)

				return ret;

			if (clear_user((void __user *) maddr, disp))

				return -EFAULT;

			maddr += disp;

		}
@@ -1164,19 +1162,17 @@ static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params, 
		if (prot & PROT_WRITE && excess1 > 0) {

			kdebug("clear[%d] ad=%lx sz=%lx",

			       loop, maddr + phdr->p_filesz, excess1);

			ret = clear_user((void __user *) maddr + phdr->p_filesz,

					 excess1);

			if (ret)

				return ret;

			if (clear_user((void __user *) maddr + phdr->p_filesz,

				       excess1))

				return -EFAULT;

		}



#else

		if (excess > 0) {

			kdebug("clear[%d] ad=%lx sz=%lx",

			       loop, maddr + phdr->p_filesz, excess);

			ret = clear_user((void *) maddr + phdr->p_filesz, excess);

			if (ret)

				return ret;

			if (clear_user((void *) maddr + phdr->p_filesz, excess))

				return -EFAULT;

		}

#endif