user/sven/linux.git/lib/vsprintf.c, branch v3.10.34

vsprintf: check real user/group id for %pK

2013-12-04T18:56:06Z

commit 312b4e226951f707e120b95b118cbc14f3d162b2 upstream. Some setuid binaries will allow reading of files which have read permission by the real user id. This is problematic with files which use %pK because the file access permission is checked at open() time, but the kptr_restrict setting is checked at read() time. If a setuid binary opens a %pK file as an unprivileged user, and then elevates permissions before reading the file, then kernel pointer values may be leaked. This happens for example with the setuid pppd application on Ubuntu 12.04: $ head -1 /proc/kallsyms 00000000 T startup_32 $ pppd file /proc/kallsyms pppd: In file /proc/kallsyms: unrecognized option 'c1000000' This will only leak the pointer value from the first line, but other setuid binaries may leak more information. Fix this by adding a check that in addition to the current process having CAP_SYSLOG, that effective user and group ids are equal to the real ids. If a setuid binary reads the contents of a file which uses %pK then the pointer values will be printed as NULL if the real user is unprivileged. Update the sysctl documentation to reflect the changes, and also correct the documentation to state the kptr_restrict=0 is the default. This is a only temporary solution to the issue. The correct solution is to do the permission check at open() time on files, and to replace %pK with a function which checks the open() time permission. %pK uses in printk should be removed since no sane permission check can be done, and instead protected by using dmesg_restrict. Signed-off-by: Ryan Mallon Cc: Kees Cook Cc: Alexander Viro Cc: Joe Perches Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

vsprintf: Add extension %pSR - print_symbol replacement

2013-04-30T20:31:16Z

print_symbol takes a long and converts it to a function name and offset. %pS does something similar, but doesn't translate the address via __builtin_extract_return_addr. %pSR does the translation. This will enable replacing multiple calls like printk(...); printk_symbol(addr); printk("\n"); with a single non-interleavable in dmesg printk("... %pSR\n", (void *)addr); Update documentation too. Signed-off-by: Joe Perches Signed-off-by: Jiri Kosina

lib/vsprintf.c: add %pa format specifier for phys_addr_t types

2013-02-22T01:22:20Z

Add the %pa format specifier for printing a phys_addr_t type and its derivative types (such as resource_size_t), since the physical address size on some platforms can vary based on build options, regardless of the native integer type. Signed-off-by: Stepan Moskovchenko Cc: Rob Landley Cc: George Spelvin Cc: Andy Shevchenko Cc: Stephen Boyd Cc: Andrei Emeltchenko Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

simple_strto*: annotate function as obsolete

2012-12-18T01:15:22Z

Update the documentation for simple_strto* to reflect that it has been obsoleted and advise the usage of kstrto*. Signed-off-by: Eldad Zack Cc: J. Bruce Fields Cc: Joe Perches Cc: Randy Dunlap Cc: Alexey Dobriyan Cc: Rob Landley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sscanf: don't ignore field widths for numeric conversions

2012-12-18T01:15:18Z

This is another step towards better standard conformance. Rather than adding a local buffer to store the specified portion of the string (with the need to enforce an arbitrary maximum supported width to limit the buffer size), do a maximum width conversion and then drop as much of it as is necessary to meet the caller's request. Also fail on negative field widths. Uses the deprecated simple_strto*() functions because kstrtoXX() fail on non-zero terminated strings. Signed-off-by: Jan Beulich Cc: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib/vsprintf.c: fix handling of %zd when using ssize_t

2012-12-18T01:15:13Z

Documentation/printk-formats.txt says to use %zd for a ssize_t argument and some drivers do. Unfortunately this prints a positive number for negative values eg: tpm_tis 70030000.tpm_tis: tpm_transmit: tpm_send: error 4294967234 Add a case to va_args a ssize_t type if the interpretation should be signed. Tested on PPC32. Signed-off-by: Jason Gunthorpe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib/vsprintf.c: improve standard conformance of sscanf()

2012-10-05T18:04:58Z

Xen's pciback points out a couple of deficiencies with vsscanf()'s standard conformance: - Trailing character matching cannot be checked by the caller: With a format string of "(%x:%x.%x) %n" absence of the closing parenthesis cannot be checked, as input of "(00:00.0)" doesn't cause the %n to be evaluated (because of the code not skipping white space before the trailing %n). - The parameter corresponding to a trailing %n could get filled even if there was a matching error: With a format string of "(%x:%x.%x)%n", input of "(00:00.0]" would still fill the respective variable pointed to (and hence again make the mismatch non-detectable by the caller). This patch aims at fixing those, but leaves other non-conforming aspects of it untouched, among them these possibly relevant ones: - improper handling of the assignment suppression character '*' (blindly discarding all succeeding non-white space from the format and input strings), - not honoring conversion specifiers for %n, - not recognizing the C99 conversion specifier 't' (recognized by vsprintf()). Signed-off-by: Jan Beulich Cc: Konrad Rzeszutek Wilk Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib/vsprintf: update documentation to cover all of %p[Mm][FR]

2012-10-05T18:04:50Z

Acked-by: Andrei Emeltchenko Signed-off-by: Andy Shevchenko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib: vsprintf: fix broken comments

2012-10-05T18:04:49Z

Numbering the 8 potential digits 2 though 9 never did make a lot of sense. Signed-off-by: George Spelvin Cc: Denys Vlasenko Cc: Michal Nazarewicz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lib: vsprintf: optimize put_dec_trunc8()

2012-10-05T18:04:49Z

If you're going to have a conditional branch after each 32x32->64-bit multiply, might as well shrink the code and make it a loop. This also avoids using the long multiply for small integers. (This leaves the comments in a confusing state, but that's a separate patch to make review easier.) Signed-off-by: George Spelvin Cc: Denys Vlasenko Cc: Michal Nazarewicz Cc: Rabin Vincent Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds