diff options
| author | Mark Wielaard <[email protected]> | 2018-06-12 12:22:13 +0200 |
|---|---|---|
| committer | Mark Wielaard <[email protected]> | 2018-06-17 00:56:05 +0200 |
| commit | cfe65047ad96500a8786625ef949099ec5671774 (patch) | |
| tree | 7d9d8c3778881299e6a8366d5d83d8ab11300027 | |
| parent | 29a3395004643c4e412a47cec5de10f63c23f13c (diff) | |
readelf: Make sure print_form_data always consumes DW_FORM_strx[1234] data.
Found by afl-fuzz. When printing DW_FORM_strx[1234] data eu-readelf didn't
increase readp which meant eu-readelf would keep printing the same line
dirs or files encoded with strx[1234] names. This meant that for insane
large dir or file counts eu-readelf would just keep printing endlessly
because we never reached and of the .debug_line buffer.
Signed-off-by: Mark Wielaard <[email protected]>
| -rw-r--r-- | libdw/ChangeLog | 4 | ||||
| -rw-r--r-- | libdw/memory-access.h | 5 | ||||
| -rw-r--r-- | src/ChangeLog | 5 | ||||
| -rw-r--r-- | src/readelf.c | 12 |
4 files changed, 20 insertions, 6 deletions
diff --git a/libdw/ChangeLog b/libdw/ChangeLog index 78321654..6492c976 100644 --- a/libdw/ChangeLog +++ b/libdw/ChangeLog @@ -1,5 +1,9 @@ 2018-06-12 Mark Wielaard <[email protected]> + * memory-access.h (read_3ubyte_unaligned_inc): New define. + +2018-06-12 Mark Wielaard <[email protected]> + * libdw.h (__libdw_dieabbrev): Set die->abbrev to DWARF_END_ABBREV on failure. diff --git a/libdw/memory-access.h b/libdw/memory-access.h index 22918cb9..a39ad6d2 100644 --- a/libdw/memory-access.h +++ b/libdw/memory-access.h @@ -362,6 +362,11 @@ read_3ubyte_unaligned (Dwarf *dbg, const unsigned char *p) } +#define read_3ubyte_unaligned_inc(Dbg, Addr) \ + ({ uint32_t t_ = read_2ubyte_unaligned (Dbg, Addr); \ + Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 3); \ + t_; }) + #define read_addr_unaligned_inc(Nbytes, Dbg, Addr) \ (assert ((Nbytes) == 4 || (Nbytes) == 8), \ ((Nbytes) == 4 ? read_4ubyte_unaligned_inc (Dbg, Addr) \ diff --git a/src/ChangeLog b/src/ChangeLog index 3d266e23..d401da27 100644 --- a/src/ChangeLog +++ b/src/ChangeLog @@ -1,3 +1,8 @@ +2018-06-12 Mark Wielaard <[email protected]> + + * readelf.c (print_form_data): Don't increase strreadp after use. + Do increase readp for DW_FORM_strx[1234]. + 2018-06-16 Mark Wielaard <[email protected]> * readelf.c (print_debug_loc_section): Make sure next_off doesn't diff --git a/src/readelf.c b/src/readelf.c index 720d7f3f..a6173806 100644 --- a/src/readelf.c +++ b/src/readelf.c @@ -8074,9 +8074,9 @@ print_form_data (Dwarf *dbg, int form, const unsigned char *readp, { Dwarf_Off idx; if (offset_len == 8) - idx = read_8ubyte_unaligned_inc (dbg, strreadp); + idx = read_8ubyte_unaligned (dbg, strreadp); else - idx = read_4ubyte_unaligned_inc (dbg, strreadp); + idx = read_4ubyte_unaligned (dbg, strreadp); data = dbg->sectiondata[IDX_debug_str]; if (data == NULL || idx >= data->d_size @@ -8093,25 +8093,25 @@ print_form_data (Dwarf *dbg, int form, const unsigned char *readp, case DW_FORM_strx1: if (readendp - readp < 1) goto invalid_data; - val = *readp; + val = *readp++; goto strx_val; case DW_FORM_strx2: if (readendp - readp < 2) goto invalid_data; - val = read_2ubyte_unaligned (dbg, readp); + val = read_2ubyte_unaligned_inc (dbg, readp); goto strx_val; case DW_FORM_strx3: if (readendp - readp < 3) goto invalid_data; - val = read_3ubyte_unaligned (dbg, readp); + val = read_3ubyte_unaligned_inc (dbg, readp); goto strx_val; case DW_FORM_strx4: if (readendp - readp < 4) goto invalid_data; - val = read_4ubyte_unaligned (dbg, readp); + val = read_4ubyte_unaligned_inc (dbg, readp); goto strx_val; default: |