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| author | Marc Dionne <marc.dionne@auristor.com> | 2024-10-31 07:55:34 -0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-11-11 13:09:43 -0800 |
| commit | e3d37a6f62953962102607fe4491129271510990 (patch) | |
| tree | 099d7d066b82d7aaff9f859c8cd3e866e57a37a9 /tools/mm | |
| parent | 431e10601913f8f2006f3ed607e73eedf264b426 (diff) | |
| download | lwn-e3d37a6f62953962102607fe4491129271510990.tar.gz lwn-e3d37a6f62953962102607fe4491129271510990.zip | |
tools/mm: fix slabinfo crash when MAX_SLABS is exceeded
The number of slabs can easily exceed the hard coded MAX_SLABS in the
slabinfo tool, causing it to overwrite memory and crash.
Increase the value of MAX_SLABS, and check if that has been exceeded for
each new slab, instead of at the end when it's already too late. Also
move the check for MAX_ALIASES into the loop body.
Link: https://lkml.kernel.org/r/20241031105534.565533-1-marc.c.dionne@gmail.com
Signed-off-by: Marc Dionne <marc.dionne@auristor.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'tools/mm')
| -rw-r--r-- | tools/mm/slabinfo.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/tools/mm/slabinfo.c b/tools/mm/slabinfo.c index 04e9e6ba86ea..1433eff99feb 100644 --- a/tools/mm/slabinfo.c +++ b/tools/mm/slabinfo.c @@ -21,7 +21,7 @@ #include <regex.h> #include <errno.h> -#define MAX_SLABS 500 +#define MAX_SLABS 2000 #define MAX_ALIASES 500 #define MAX_NODES 1024 @@ -1228,6 +1228,8 @@ static void read_slab_dir(void) continue; switch (de->d_type) { case DT_LNK: + if (alias - aliasinfo == MAX_ALIASES) + fatal("Too many aliases\n"); alias->name = strdup(de->d_name); count = readlink(de->d_name, buffer, sizeof(buffer)-1); @@ -1242,6 +1244,8 @@ static void read_slab_dir(void) alias++; break; case DT_DIR: + if (slab - slabinfo == MAX_SLABS) + fatal("Too many slabs\n"); if (chdir(de->d_name)) fatal("Unable to access slab %s\n", slab->name); slab->name = strdup(de->d_name); @@ -1312,10 +1316,6 @@ static void read_slab_dir(void) slabs = slab - slabinfo; actual_slabs = slabs; aliases = alias - aliasinfo; - if (slabs > MAX_SLABS) - fatal("Too many slabs\n"); - if (aliases > MAX_ALIASES) - fatal("Too many aliases\n"); } static void output_slabs(void) |