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[PATCH] flat binary loader doesn't check fd table full
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In binfmt_flat.c, the flat binary loader should check file descriptor table
and install the fd on the file.

Convert the function to single-exit and fix this bug.

Signed-off-by: "Luke Yang" <luke.adi@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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Luke Yang authored and Linus Torvalds committed Mar 25, 2006
1 parent f516342 commit 1ad3dcc
Showing 1 changed file with 54 additions and 19 deletions.
73 changes: 54 additions & 19 deletions fs/binfmt_flat.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,7 @@
#include <linux/personality.h>
#include <linux/init.h>
#include <linux/flat.h>
#include <linux/syscalls.h>

#include <asm/byteorder.h>
#include <asm/system.h>
Expand Down Expand Up @@ -426,6 +427,8 @@ static int load_flat_file(struct linux_binprm * bprm,
int i, rev, relocs = 0;
loff_t fpos;
unsigned long start_code, end_code;
int ret;
int exec_fileno;

hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
inode = bprm->file->f_dentry->d_inode;
Expand All @@ -450,22 +453,25 @@ static int load_flat_file(struct linux_binprm * bprm,
*/
if (strncmp(hdr->magic, "#!", 2))
printk("BINFMT_FLAT: bad header magic\n");
return -ENOEXEC;
ret = -ENOEXEC;
goto err;
}

if (flags & FLAT_FLAG_KTRACE)
printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);

if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
printk("BINFMT_FLAT: bad flat file version 0x%x (supported 0x%x and 0x%x)\n", rev, FLAT_VERSION, OLD_FLAT_VERSION);
return -ENOEXEC;
ret = -ENOEXEC;
goto err;
}

/* Don't allow old format executables to use shared libraries */
if (rev == OLD_FLAT_VERSION && id != 0) {
printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
(int) FLAT_VERSION);
return -ENOEXEC;
ret = -ENOEXEC;
goto err;
}

/*
Expand All @@ -478,7 +484,8 @@ static int load_flat_file(struct linux_binprm * bprm,
#ifndef CONFIG_BINFMT_ZFLAT
if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
printk("Support for ZFLAT executables is not enabled.\n");
return -ENOEXEC;
ret = -ENOEXEC;
goto err;
}
#endif

Expand All @@ -490,14 +497,27 @@ static int load_flat_file(struct linux_binprm * bprm,
rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
if (rlim >= RLIM_INFINITY)
rlim = ~0;
if (data_len + bss_len > rlim)
return -ENOMEM;
if (data_len + bss_len > rlim) {
ret = -ENOMEM;
goto err;
}

/* check file descriptor */
exec_fileno = get_unused_fd();
if (exec_fileno < 0) {
ret = -EMFILE;
goto err;
}
get_file(bprm->file);
fd_install(exec_fileno, bprm->file);

/* Flush all traces of the currently running executable */
if (id == 0) {
result = flush_old_exec(bprm);
if (result)
return result;
if (result) {
ret = result;
goto err_close;
}

/* OK, This is the point of no return */
set_personality(PER_LINUX);
Expand Down Expand Up @@ -527,7 +547,8 @@ static int load_flat_file(struct linux_binprm * bprm,
if (!textpos)
textpos = (unsigned long) -ENOMEM;
printk("Unable to mmap process text, errno %d\n", (int)-textpos);
return(textpos);
ret = textpos;
goto err_close;
}

down_write(&current->mm->mmap_sem);
Expand All @@ -542,7 +563,8 @@ static int load_flat_file(struct linux_binprm * bprm,
printk("Unable to allocate RAM for process data, errno %d\n",
(int)-datapos);
do_munmap(current->mm, textpos, text_len);
return realdatastart;
ret = realdatastart;
goto err_close;
}
datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);

Expand All @@ -564,7 +586,8 @@ static int load_flat_file(struct linux_binprm * bprm,
printk("Unable to read data+bss, errno %d\n", (int)-result);
do_munmap(current->mm, textpos, text_len);
do_munmap(current->mm, realdatastart, data_len + extra);
return result;
ret = result;
goto err_close;
}

reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
Expand All @@ -582,7 +605,8 @@ static int load_flat_file(struct linux_binprm * bprm,
textpos = (unsigned long) -ENOMEM;
printk("Unable to allocate RAM for process text/data, errno %d\n",
(int)-textpos);
return(textpos);
ret = textpos;
goto err_close;
}

realdatastart = textpos + ntohl(hdr->data_start);
Expand Down Expand Up @@ -627,7 +651,8 @@ static int load_flat_file(struct linux_binprm * bprm,
printk("Unable to read code+data+bss, errno %d\n",(int)-result);
do_munmap(current->mm, textpos, text_len + data_len + extra +
MAX_SHARED_LIBS * sizeof(unsigned long));
return result;
ret = result;
goto err_close;
}
}

Expand Down Expand Up @@ -690,8 +715,10 @@ static int load_flat_file(struct linux_binprm * bprm,
unsigned long addr;
if (*rp) {
addr = calc_reloc(*rp, libinfo, id, 0);
if (addr == RELOC_FAILED)
return -ENOEXEC;
if (addr == RELOC_FAILED) {
ret = -ENOEXEC;
goto err_close;
}
*rp = addr;
}
}
Expand All @@ -718,8 +745,10 @@ static int load_flat_file(struct linux_binprm * bprm,
relval = ntohl(reloc[i]);
addr = flat_get_relocate_addr(relval);
rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
if (rp == (unsigned long *)RELOC_FAILED)
return -ENOEXEC;
if (rp == (unsigned long *)RELOC_FAILED) {
ret = -ENOEXEC;
goto err_close;
}

/* Get the pointer's value. */
addr = flat_get_addr_from_rp(rp, relval, flags);
Expand All @@ -731,8 +760,10 @@ static int load_flat_file(struct linux_binprm * bprm,
if ((flags & FLAT_FLAG_GOTPIC) == 0)
addr = ntohl(addr);
addr = calc_reloc(addr, libinfo, id, 0);
if (addr == RELOC_FAILED)
return -ENOEXEC;
if (addr == RELOC_FAILED) {
ret = -ENOEXEC;
goto err_close;
}

/* Write back the relocated pointer. */
flat_put_addr_at_rp(rp, addr, relval);
Expand All @@ -752,6 +783,10 @@ static int load_flat_file(struct linux_binprm * bprm,
stack_len);

return 0;
err_close:
sys_close(exec_fileno);
err:
return ret;
}


Expand Down

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