Re: [Crash-utility] [PATCH v3] Basic support for PaX's split module layout

Does this need further input from my site to get merged? Lianbo acked an earlier version[1], so this should be fine as is?

Thanks, Mathias [1] https://www.redhat.com/archives/crash-utility/2020-August/msg00021.html Am 25.08.20 um 04:09 schrieb HAGIO KAZUHITO(萩尾 一仁): > -----Original Message----- >> PaX and grsecurity kernels split module memory into dedicated r/x and >> r/w mappings using '*_rw' and '*_rx' named member variables in 'struct >> module'. To add basic support for such kernels detect the split layout >> by testing for the corresponding structure members and use these >> instead. >> >> So far we limit ourself to only track module code mappings for such >> kernels as adding support for separate data mappings violates lots of >> invariants in the rest of our code base, thereby would require a major >> rework. However, with that patch applied, module code references can be >> resolved in backtraces, memory and code dumps, which makes it already >> very useful for analyzing such kernels. >> >> Signed-off-by: Mathias Krause <minipli(a)grsecurity.net&gt; >> --- >> v3: >> - dump offsets unconditional >> - fix indention of 'module_init_size' offset dump > > Thanks for the update. The v3 patch looks good to me. > > Acked-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; > > Thanks, > Kazu > >> >> v2: >> - add members to end of struct offset_table >> - add offsets to dump_offset_table() >> >> defs.h | 13 +++++++++++ >> kernel.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++---- >> symbols.c | 38 ++++++++++++++++++++++--------- >> 3 files changed, 103 insertions(+), 16 deletions(-) >> >> diff --git a/defs.h b/defs.h >> index 17e98763362b..ae860448ab15 100644 >> --- a/defs.h >> +++ b/defs.h >> @@ -654,12 +654,15 @@ struct new_utsname { >> #define TIMER_BASES (0x20ULL) >> #define IRQ_DESC_TREE_RADIX (0x40ULL) >> #define IRQ_DESC_TREE_XARRAY (0x80ULL) >> +#define KMOD_PAX (0x100ULL) >> >> #define XEN() (kt->flags & ARCH_XEN) >> #define OPENVZ() (kt->flags & ARCH_OPENVZ) >> #define PVOPS() (kt->flags & ARCH_PVOPS) >> #define PVOPS_XEN() (kt->flags & ARCH_PVOPS_XEN) >> >> +#define PAX_MODULE_SPLIT() (kt->flags2 & KMOD_PAX) >> + >> #define XEN_MACHINE_TO_MFN(m) ((ulonglong)(m) >> PAGESHIFT()) >> #define XEN_PFN_TO_PSEUDO(p) ((ulonglong)(p) << PAGESHIFT()) >> >> @@ -2089,6 +2092,14 @@ struct offset_table { /* stash of commonly-used offsets */ >> long size_class_size; >> long gendisk_private_data; >> long zram_table_entry; >> + long module_core_size_rw; >> + long module_core_size_rx; >> + long module_init_size_rw; >> + long module_init_size_rx; >> + long module_module_core_rw; >> + long module_module_core_rx; >> + long module_module_init_rw; >> + long module_module_init_rx; >> }; >> >> struct size_table { /* stash of commonly-used sizes */ >> @@ -2313,6 +2324,8 @@ struct array_table { >> * in the offset table, size table or array_table. >> */ >> #define OFFSET(X) (OFFSET_verify(offset_table.X, (char *)__FUNCTION__, __FILE__, __LINE__, #X)) >> +#define MODULE_OFFSET(X,Y) (PAX_MODULE_SPLIT() ? OFFSET(Y) : OFFSET(X)) >> +#define MODULE_OFFSET2(X,T) MODULE_OFFSET(X, X##_##T) >> #define SIZE(X) (SIZE_verify(size_table.X, (char *)__FUNCTION__, __FILE__, __LINE__, #X)) >> #define INVALID_OFFSET (-1) >> #define INVALID_MEMBER(X) (offset_table.X == INVALID_OFFSET) >> diff --git a/kernel.c b/kernel.c >> index f179375f2d3d..f0268adccd4a 100644 >> --- a/kernel.c >> +++ b/kernel.c >> @@ -3540,6 +3540,62 @@ module_init(void) >> "module_core"); >> MEMBER_OFFSET_INIT(module_module_init, "module", >> "module_init"); >> + } else if (MEMBER_EXISTS("module", "module_core_rx")) { >> + if (CRASHDEBUG(1)) >> + error(INFO, "PaX module layout detected.\n"); >> + kt->flags2 |= KMOD_PAX; >> + >> + MEMBER_OFFSET_INIT(module_core_size_rw, "module", >> + "core_size_rw"); >> + MEMBER_OFFSET_INIT(module_core_size_rx, "module", >> + "core_size_rx"); >> + >> + MEMBER_OFFSET_INIT(module_init_size_rw, "module", >> + "init_size_rw"); >> + MEMBER_OFFSET_INIT(module_init_size_rx, "module", >> + "init_size_rx"); >> + >> + MEMBER_OFFSET_INIT(module_module_core_rw, "module", >> + "module_core_rw"); >> + MEMBER_OFFSET_INIT(module_module_core_rx, "module", >> + "module_core_rx"); >> + >> + MEMBER_OFFSET_INIT(module_module_init_rw, "module", >> + "module_init_rw"); >> + MEMBER_OFFSET_INIT(module_module_init_rx, "module", >> + "module_init_rx"); >> + } else if (MEMBER_EXISTS("module_layout", "base_rx")) { >> + if (CRASHDEBUG(1)) >> + error(INFO, "PaX module layout detected.\n"); >> + kt->flags2 |= KMOD_PAX; >> + >> + ASSIGN_OFFSET(module_core_size_rw) = >> + MEMBER_OFFSET("module", "core_layout") + >> + MEMBER_OFFSET("module_layout", "size_rw"); >> + ASSIGN_OFFSET(module_core_size_rx) = >> + MEMBER_OFFSET("module", "core_layout") + >> + MEMBER_OFFSET("module_layout", "size_rx"); >> + >> + ASSIGN_OFFSET(module_init_size_rw) = >> + MEMBER_OFFSET("module", "init_layout") + >> + MEMBER_OFFSET("module_layout", "size_rw"); >> + ASSIGN_OFFSET(module_init_size_rx) = >> + MEMBER_OFFSET("module", "init_layout") + >> + MEMBER_OFFSET("module_layout", "size_rx"); >> + >> + ASSIGN_OFFSET(module_module_core_rw) = >> + MEMBER_OFFSET("module", "core_layout") + >> + MEMBER_OFFSET("module_layout", "base_rw"); >> + ASSIGN_OFFSET(module_module_core_rx) = >> + MEMBER_OFFSET("module", "core_layout") + >> + MEMBER_OFFSET("module_layout", "base_rx"); >> + >> + ASSIGN_OFFSET(module_module_init_rw) = >> + MEMBER_OFFSET("module", "init_layout") + >> + MEMBER_OFFSET("module_layout", "base_rw"); >> + ASSIGN_OFFSET(module_module_init_rx) = >> + MEMBER_OFFSET("module", "init_layout") + >> + MEMBER_OFFSET("module_layout", "base_rx"); >> } else { >> ASSIGN_OFFSET(module_core_size) = >> MEMBER_OFFSET("module", "core_layout") + >> @@ -3682,10 +3738,10 @@ module_init(void) >> case KALLSYMS_V2: >> if (THIS_KERNEL_VERSION >= LINUX(2,6,27)) { >> numksyms = UINT(modbuf + OFFSET(module_num_symtab)); >> - size = UINT(modbuf + OFFSET(module_core_size)); >> + size = UINT(modbuf + MODULE_OFFSET2(module_core_size, rx)); >> } else { >> numksyms = ULONG(modbuf + OFFSET(module_num_symtab)); >> - size = ULONG(modbuf + OFFSET(module_core_size)); >> + size = ULONG(modbuf + MODULE_OFFSET2(module_core_size, rx)); >> } >> >> if (!size) { >> @@ -3792,7 +3848,7 @@ verify_modules(void) >> break; >> case KMOD_V2: >> mod_base = ULONG(modbuf + >> - OFFSET(module_module_core)); >> + MODULE_OFFSET2(module_module_core, rx)); >> break; >> } >> >> @@ -3816,10 +3872,10 @@ verify_modules(void) >> OFFSET(module_name); >> if (THIS_KERNEL_VERSION >= LINUX(2,6,27)) >> mod_size = UINT(modbuf + >> - OFFSET(module_core_size)); >> + MODULE_OFFSET2(module_core_size, rx)); >> else >> mod_size = ULONG(modbuf + >> - OFFSET(module_core_size)); >> + MODULE_OFFSET2(module_core_size, rx)); >> if (strlen(module_name) < MAX_MOD_NAME) >> strcpy(buf, module_name); >> else >> @@ -5997,6 +6053,8 @@ dump_kernel_table(int verbose) >> fprintf(fp, "%sIRQ_DESC_TREE_RADIX", others++ ? "|" : ""); >> if (kt->flags2 & IRQ_DESC_TREE_XARRAY) >> fprintf(fp, "%sIRQ_DESC_TREE_XARRAY", others++ ? "|" : ""); >> + if (kt->flags2 & KMOD_PAX) >> + fprintf(fp, "%sKMOD_PAX", others++ ? "|" : ""); >> fprintf(fp, ")\n"); >> >> fprintf(fp, " stext: %lx\n", kt->stext); >> diff --git a/symbols.c b/symbols.c >> index 2fecaee093a2..311fdb7df29e 100644 >> --- a/symbols.c >> +++ b/symbols.c >> @@ -1766,17 +1766,17 @@ store_module_symbols_v2(ulong total, int mods_installed) >> >> if (THIS_KERNEL_VERSION >= LINUX(2,6,27)) { >> nksyms = UINT(modbuf + OFFSET(module_num_symtab)); >> - size = UINT(modbuf + OFFSET(module_core_size)); >> + size = UINT(modbuf + MODULE_OFFSET2(module_core_size, rx)); >> } else { >> nksyms = ULONG(modbuf + OFFSET(module_num_symtab)); >> - size = ULONG(modbuf + OFFSET(module_core_size)); >> + size = ULONG(modbuf + MODULE_OFFSET2(module_core_size, rx)); >> } >> >> mod_name = modbuf + OFFSET(module_name); >> >> lm = &st->load_modules[m++]; >> BZERO(lm, sizeof(struct load_module)); >> - lm->mod_base = ULONG(modbuf + OFFSET(module_module_core)); >> + lm->mod_base = ULONG(modbuf + MODULE_OFFSET2(module_module_core, rx)); >> lm->module_struct = mod; >> lm->mod_size = size; >> if (strlen(mod_name) < MAX_MOD_NAME) >> @@ -1795,23 +1795,23 @@ store_module_symbols_v2(ulong total, int mods_installed) >> lm->mod_flags = MOD_EXT_SYMS; >> lm->mod_ext_symcnt = mcnt; >> lm->mod_init_module_ptr = ULONG(modbuf + >> - OFFSET(module_module_init)); >> + MODULE_OFFSET2(module_module_init, rx)); >> if (VALID_MEMBER(module_percpu)) >> lm->mod_percpu = ULONG(modbuf + OFFSET(module_percpu)); >> if (THIS_KERNEL_VERSION >= LINUX(2,6,27)) { >> lm->mod_etext_guess = lm->mod_base + >> - UINT(modbuf + OFFSET(module_core_text_size)); >> + UINT(modbuf + MODULE_OFFSET(module_core_text_size, module_core_size_rx)); >> lm->mod_init_size = >> - UINT(modbuf + OFFSET(module_init_size)); >> + UINT(modbuf + MODULE_OFFSET2(module_init_size, rx)); >> lm->mod_init_text_size = >> - UINT(modbuf + OFFSET(module_init_text_size)); >> + UINT(modbuf + MODULE_OFFSET(module_init_text_size, module_init_size_rx)); >> } else { >> lm->mod_etext_guess = lm->mod_base + >> - ULONG(modbuf + OFFSET(module_core_text_size)); >> + ULONG(modbuf + MODULE_OFFSET(module_core_text_size, module_core_size_rx)); >> lm->mod_init_size = >> - ULONG(modbuf + OFFSET(module_init_size)); >> + ULONG(modbuf + MODULE_OFFSET2(module_init_size, rx)); >> lm->mod_init_text_size = >> - ULONG(modbuf + OFFSET(module_init_text_size)); >> + ULONG(modbuf + MODULE_OFFSET(module_init_text_size, module_init_size_rx)); >> } >> lm->mod_text_start = lm->mod_base; >> >> @@ -9119,12 +9119,28 @@ dump_offset_table(char *spec, ulong makestruct) >> OFFSET(module_core_size)); >> fprintf(fp, " module_core_text_size: %ld\n", >> OFFSET(module_core_text_size)); >> - fprintf(fp, " module_init_size: %ld\n", >> + fprintf(fp, " module_init_size: %ld\n", >> OFFSET(module_init_size)); >> fprintf(fp, " module_init_text_size: %ld\n", >> OFFSET(module_init_text_size)); >> fprintf(fp, " module_module_init: %ld\n", >> OFFSET(module_module_init)); >> + fprintf(fp, " module_module_core_rx: %ld\n", >> + OFFSET(module_module_core_rx)); >> + fprintf(fp, " module_module_core_rw: %ld\n", >> + OFFSET(module_module_core_rw)); >> + fprintf(fp, " module_core_size_rx: %ld\n", >> + OFFSET(module_core_size_rx)); >> + fprintf(fp, " module_core_size_rw: %ld\n", >> + OFFSET(module_core_size_rw)); >> + fprintf(fp, " module_module_init_rx: %ld\n", >> + OFFSET(module_module_init_rx)); >> + fprintf(fp, " module_module_init_rw: %ld\n", >> + OFFSET(module_module_init_rw)); >> + fprintf(fp, " module_init_size_rx: %ld\n", >> + OFFSET(module_init_size_rx)); >> + fprintf(fp, " module_init_size_rw: %ld\n", >> + OFFSET(module_init_size_rw)); >> fprintf(fp, " module_num_symtab: %ld\n", >> OFFSET(module_num_symtab)); >> fprintf(fp, " module_symtab: %ld\n", >> -- >> 2.20.1 >> >> >> -- >> Crash-utility mailing list >> Crash-utility(a)redhat.com >> https://www.redhat.com/mailman/listinfo/crash-utility > > > -- > Crash-utility mailing list > Crash-utility(a)redhat.com > https://www.redhat.com/mailman/listinfo/crash-utility >