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Subject[PATCH] elf: free PT_INTERP filename ASAP
There is no reason for PT_INTERP filename to linger till the end of
the whole loading process.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

fs/binfmt_elf.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)

--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -686,7 +686,6 @@ static int load_elf_binary(struct linux_binprm *bprm)
struct file *interpreter = NULL; /* to shut gcc up */
unsigned long load_addr = 0, load_bias = 0;
int load_addr_set = 0;
- char * elf_interpreter = NULL;
unsigned long error;
struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL;
unsigned long elf_bss, elf_brk;
@@ -742,6 +741,7 @@ static int load_elf_binary(struct linux_binprm *bprm)

for (i = 0; i < loc->elf_ex.e_phnum; i++) {
if (elf_ppnt->p_type == PT_INTERP) {
+ char *elf_interpreter;
loff_t pos;

/* This is the program interpreter used for
@@ -773,9 +773,10 @@ static int load_elf_binary(struct linux_binprm *bprm)
goto out_free_interp;

interpreter = open_exec(elf_interpreter);
+ kfree(elf_interpreter);
retval = PTR_ERR(interpreter);
if (IS_ERR(interpreter))
- goto out_free_interp;
+ goto out_free_dentry;

/*
* If the binary is not readable then enforce
@@ -795,6 +796,10 @@ static int load_elf_binary(struct linux_binprm *bprm)
}

break;
+
+out_free_interp:
+ kfree(elf_interpreter);
+ goto out_free_ph;
}
elf_ppnt++;
}
@@ -819,7 +824,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
}

/* Some simple consistency checks for the interpreter */
- if (elf_interpreter) {
+ if (interpreter) {
retval = -ELIBBAD;
/* Not an ELF interpreter */
if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
@@ -978,7 +983,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
* independently randomized mmap region (0 load_bias
* without MAP_FIXED).
*/
- if (elf_interpreter) {
+ if (interpreter) {
load_bias = ELF_ET_DYN_BASE;
if (current->flags & PF_RANDOMIZE)
load_bias += arch_mmap_rnd();
@@ -1076,7 +1081,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
goto out_free_dentry;
}

- if (elf_interpreter) {
+ if (interpreter) {
unsigned long interp_map_addr = 0;

elf_entry = load_elf_interp(&loc->interp_elf_ex,
@@ -1100,7 +1105,6 @@ static int load_elf_binary(struct linux_binprm *bprm)

allow_write_access(interpreter);
fput(interpreter);
- kfree(elf_interpreter);
} else {
elf_entry = loc->elf_ex.e_entry;
if (BAD_ADDR(elf_entry)) {
@@ -1115,7 +1119,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
set_binfmt(&elf_format);

#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
- retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
+ retval = arch_setup_additional_pages(bprm, !!interpreter);
if (retval < 0)
goto out;
#endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
@@ -1177,8 +1181,6 @@ static int load_elf_binary(struct linux_binprm *bprm)
allow_write_access(interpreter);
if (interpreter)
fput(interpreter);
-out_free_interp:
- kfree(elf_interpreter);
out_free_ph:
kfree(elf_phdata);
goto out;
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