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authorLinus Torvalds <torvalds@linux-foundation.org>2018-10-24 06:22:39 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-24 06:22:39 -0400
commitba9f6f8954afa5224e3ed60332f7b92242b7ed0f (patch)
treee6513afc476231dc2242728ffbf51353936b46af /fs/binfmt_elf.c
parenta978a5b8d83f795e107a2ff759b28643739be70e (diff)
parenta36700589b85443e28170be59fa11c8a104130a5 (diff)
Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull siginfo updates from Eric Biederman: "I have been slowly sorting out siginfo and this is the culmination of that work. The primary result is in several ways the signal infrastructure has been made less error prone. The code has been updated so that manually specifying SEND_SIG_FORCED is never necessary. The conversion to the new siginfo sending functions is now complete, which makes it difficult to send a signal without filling in the proper siginfo fields. At the tail end of the patchset comes the optimization of decreasing the size of struct siginfo in the kernel from 128 bytes to about 48 bytes on 64bit. The fundamental observation that enables this is by definition none of the known ways to use struct siginfo uses the extra bytes. This comes at the cost of a small user space observable difference. For the rare case of siginfo being injected into the kernel only what can be copied into kernel_siginfo is delivered to the destination, the rest of the bytes are set to 0. For cases where the signal and the si_code are known this is safe, because we know those bytes are not used. For cases where the signal and si_code combination is unknown the bits that won't fit into struct kernel_siginfo are tested to verify they are zero, and the send fails if they are not. I made an extensive search through userspace code and I could not find anything that would break because of the above change. If it turns out I did break something it will take just the revert of a single change to restore kernel_siginfo to the same size as userspace siginfo. Testing did reveal dependencies on preferring the signo passed to sigqueueinfo over si->signo, so bit the bullet and added the complexity necessary to handle that case. Testing also revealed bad things can happen if a negative signal number is passed into the system calls. Something no sane application will do but something a malicious program or a fuzzer might do. So I have fixed the code that performs the bounds checks to ensure negative signal numbers are handled" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (80 commits) signal: Guard against negative signal numbers in copy_siginfo_from_user32 signal: Guard against negative signal numbers in copy_siginfo_from_user signal: In sigqueueinfo prefer sig not si_signo signal: Use a smaller struct siginfo in the kernel signal: Distinguish between kernel_siginfo and siginfo signal: Introduce copy_siginfo_from_user and use it's return value signal: Remove the need for __ARCH_SI_PREABLE_SIZE and SI_PAD_SIZE signal: Fail sigqueueinfo if si_signo != sig signal/sparc: Move EMT_TAGOVF into the generic siginfo.h signal/unicore32: Use force_sig_fault where appropriate signal/unicore32: Generate siginfo in ucs32_notify_die signal/unicore32: Use send_sig_fault where appropriate signal/arc: Use force_sig_fault where appropriate signal/arc: Push siginfo generation into unhandled_exception signal/ia64: Use force_sig_fault where appropriate signal/ia64: Use the force_sig(SIGSEGV,...) in ia64_rt_sigreturn signal/ia64: Use the generic force_sigsegv in setup_frame signal/arm/kvm: Use send_sig_mceerr signal/arm: Use send_sig_fault where appropriate signal/arm: Use force_sig_fault where appropriate ...
Diffstat (limited to 'fs/binfmt_elf.c')
-rw-r--r--fs/binfmt_elf.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index efae2fb0930a..54207327f98f 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -1580,7 +1580,7 @@ static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1580} 1580}
1581 1581
1582static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata, 1582static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1583 const siginfo_t *siginfo) 1583 const kernel_siginfo_t *siginfo)
1584{ 1584{
1585 mm_segment_t old_fs = get_fs(); 1585 mm_segment_t old_fs = get_fs();
1586 set_fs(KERNEL_DS); 1586 set_fs(KERNEL_DS);
@@ -1782,7 +1782,7 @@ static int fill_thread_core_info(struct elf_thread_core_info *t,
1782 1782
1783static int fill_note_info(struct elfhdr *elf, int phdrs, 1783static int fill_note_info(struct elfhdr *elf, int phdrs,
1784 struct elf_note_info *info, 1784 struct elf_note_info *info,
1785 const siginfo_t *siginfo, struct pt_regs *regs) 1785 const kernel_siginfo_t *siginfo, struct pt_regs *regs)
1786{ 1786{
1787 struct task_struct *dump_task = current; 1787 struct task_struct *dump_task = current;
1788 const struct user_regset_view *view = task_user_regset_view(dump_task); 1788 const struct user_regset_view *view = task_user_regset_view(dump_task);
@@ -2031,7 +2031,7 @@ static int elf_note_info_init(struct elf_note_info *info)
2031 2031
2032static int fill_note_info(struct elfhdr *elf, int phdrs, 2032static int fill_note_info(struct elfhdr *elf, int phdrs,
2033 struct elf_note_info *info, 2033 struct elf_note_info *info,
2034 const siginfo_t *siginfo, struct pt_regs *regs) 2034 const kernel_siginfo_t *siginfo, struct pt_regs *regs)
2035{ 2035{
2036 struct list_head *t; 2036 struct list_head *t;
2037 struct core_thread *ct; 2037 struct core_thread *ct;