diff options
| author | Masami Hiramatsu <mhiramat@redhat.com> | 2010-03-06 00:44:12 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-03-06 22:26:46 +0300 |
| commit | 30736a4d43f4af7f1a7836d6a266be17082195c4 (patch) | |
| tree | 54e388cdaf4795bdb7651be03c50bba67eb0b43a /fs/binfmt_elf_fdpic.c | |
| parent | 8d9032bbe4671dc481261ccd4e161cd96e54b118 (diff) | |
| download | linux-30736a4d43f4af7f1a7836d6a266be17082195c4.tar.xz | |
coredump: pass mm->flags as a coredump parameter for consistency
Pass mm->flags as a coredump parameter for consistency.
---
1787 if (mm->core_state || !get_dumpable(mm)) { <- (1)
1788 up_write(&mm->mmap_sem);
1789 put_cred(cred);
1790 goto fail;
1791 }
1792
[...]
1798 if (get_dumpable(mm) == 2) { /* Setuid core dump mode */ <-(2)
1799 flag = O_EXCL; /* Stop rewrite attacks */
1800 cred->fsuid = 0; /* Dump root private */
1801 }
---
Since dumpable bits are not protected by lock, there is a chance to change
these bits between (1) and (2).
To solve this issue, this patch copies mm->flags to
coredump_params.mm_flags at the beginning of do_coredump() and uses it
instead of get_dumpable() while dumping core.
This copy is also passed to binfmt->core_dump, since elf*_core_dump() uses
dump_filter bits in mm->flags.
[akpm@linux-foundation.org: fix merge]
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/binfmt_elf_fdpic.c')
| -rw-r--r-- | fs/binfmt_elf_fdpic.c | 14 |
1 files changed, 3 insertions, 11 deletions
diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index e49d9c06a4b6..6d6a16c5e9bb 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -1626,7 +1626,6 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm) #endif int thread_status_size = 0; elf_addr_t *auxv; - unsigned long mm_flags; struct elf_phdr *phdr4note = NULL; struct elf_shdr *shdr4extnum = NULL; Elf_Half e_phnum; @@ -1769,14 +1768,7 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm) /* Page-align dumped data */ dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); - /* - * We must use the same mm->flags while dumping core to avoid - * inconsistency between the program headers and bodies, otherwise an - * unusable core file can be generated. - */ - mm_flags = current->mm->flags; - - offset += elf_core_vma_data_size(mm_flags); + offset += elf_core_vma_data_size(cprm->mm_flags); offset += elf_core_extra_data_size(); e_shoff = offset; @@ -1809,7 +1801,7 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm) phdr.p_offset = offset; phdr.p_vaddr = vma->vm_start; phdr.p_paddr = 0; - phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0; + phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0; phdr.p_memsz = sz; offset += phdr.p_filesz; phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; @@ -1847,7 +1839,7 @@ static int elf_fdpic_core_dump(struct coredump_params *cprm) goto end_coredump; if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit, - mm_flags) < 0) + cprm->mm_flags) < 0) goto end_coredump; if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit)) |