kconfig: Avoid buffer underrun in choice input
PATCH 1/1 kconfig: Avoid buffer underrun in choice input
commit 40aee729b350672c2550640622416a855e27938f ('kconfig: fix default value for choice input') fixed some cases where kconfig would select the wrong option from a choice with a single valid option and thus enter an infinite loop.
However, this broke the test for user input of the form 'N?', because when kconfig selects the single valid option the input is zero-length and the test will read the byte before the input buffer. If this happens to contain '?' (as it will in a mips build on Debian unstable today) then kconfig again enters an infinite loop.
--- scripts/kconfig/conf.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
scripts/kconfig/conf.c +1 -1
@@ -332,7 +332,7 @@ static int conf_choice(struct menu *menu) }if (!child)continue ; -if (line[strlen (line) -1 ] =='?' ) { +if (line[0 ] && line[strlen (line) -1 ] =='?' ) {print_help (child);continue ; }
Signature · 1 line
1.7.4.1
Quoted 10 lines · Ben Hutchings
commit
40aee729b350672c2550640622416a855e27938f('kconfig: fix default value for choice input') fixed some cases where kconfig would select the wrong option from a choice with a single valid option and thus enter an infinite loop.However, this broke the test for user input of the form 'N?', because when kconfig selects the single valid option the input is zero-length and the test will read the byte before the input buffer. If this happens to contain '?' (as it will in a mips build on Debian unstable today) then kconfig again enters an infinite loop.
Please acknowledge this and send it upstream.
Ben.
Quoted 19 lines
Signed-off-by Ben Hutchings <[email protected]>Cc [email protected] [2.6.17+]--- scripts/kconfig/conf.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)scripts/kconfig/conf.c +1
-1@@ -332,7 +332,7 @@ static int conf_choice(struct menu *menu) }if (!child)continue ; -if (line[strlen (line) -1 ] =='?' ) { +if (line[0 ] && line[strlen (line) -1 ] =='?' ) {print_help (child);continue ; }
Signature · 2 lines
Ben Hutchings Once a job is fouled up, anything done to improve it makes it worse.
Quoted 11 lines · Ben Hutchings
commit
40aee729b350672c2550640622416a855e27938f('kconfig: fix default value for choice input') fixed some cases where kconfig would select the wrong option from a choice with a single valid option and thus enter an infinite loop.However, this broke the test for user input of the form 'N?', because when kconfig selects the single valid option the input is zero-length and the test will read the byte before the input buffer. If this happens to contain '?' (as it will in a mips build on Debian unstable today) then kconfig again enters an infinite loop.
Quoted 4 lines
Signed-off-by Ben Hutchings <[email protected]>Cc [email protected] [2.6.17+]--- scripts/kconfig/conf.c | 2 +-
Applied to kbuild-2.6.git#kconfig, thanks.
Michal