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charset="UTF-8" X-Rspamd-Queue-Id: C4D291C0019 X-Rspamd-Server: rspam09 X-Rspam-User: X-Stat-Signature: yo6cf1gmz3m46x78pin88ebfcx4iudeb X-HE-Tag: 1670862224-484367 X-HE-Meta: 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 42lclFfe YQG8CmvGHRV4cla0okEsWVu6UiotbTuRsE0sWiZfKfenXlVM= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Sat, Dec 10, 2022 at 3:51 PM Al Viro wrote: > > On Mon, Dec 05, 2022 at 09:51:39AM -0800, Nhat Pham wrote: > > > + if (!access_ok(cstat, sizeof(struct cachestat))) > > + return -EFAULT; > > What for? You are using copy_to_user() later, right? Oh I didn't realize copy_to_user() would suffice - mincore also has this check: if (!access_ok(vec, pages)) return -EFAULT; (even though it also has a similar check with copy_to_user), so I just erred on the side of safety and included it. If this is redundant, I'll just remove it from the next version. > > > + f = fdget(fd); > > + if (f.file) { > > It would be easier to read if you inverted the condition here. Oh I think I tried if (!f.file) return -EBADF; here, but there are some mixing-code-with-decl warnings. If I recall correctly, the problem is with this line: XA_STATE(xas, &mapping->i_pages, first_index); which is expanded into a declaration: #define XA_STATE(name, array, index) \ struct xa_state name = __XA_STATE(array, index, 0, 0) It requires a valid mapping though, which is obtained from f.file: struct address_space *mapping = f.file->f_mapping; so it cannot be moved above the if(!f.file) check either...